System Stability

Checklist for Mac OSX


Before embarking on any repair of your Mac computer:

  1. Create a separate bootable CD/DVD/USB disk. Include in the disk things like an anti-virus checker, file recovery, and all other kinds of tools you might need to test and fix your Mac computer. Use this disk to bypass the Mac's own hard disk so you can test if the problems you have on your computer are present and persistent or not. Usually this separate bootable disk provides a powerful means of determining what may have happened as the disk itself is essentially a clean OS X standard for you to do your testing. If there are obvious changes and things are clearly better on the clean bootable disk, this is your opportunity to track down the cause and perform the necessary repairs.
  2. Backup the data on your computer to a separate external and reliable hard drive. At the very least you should backup all your personal data such as budget spreadsheets and Word documents, as well as photos, movies and sound files you have created. With the cost of backup external drives down to as little as US$50 for 1 terabyte (1TB) storage capacities, there is really no excuse not to have one. And for the capacity you get, you can essentially copy the entire hard disk(s) of your Mac computer (i.e., third-party apps, and all the rest). So consider doing the latter, and only do the former of keeping personal data on a separate external drive if you feel confident the work you do to repair your computer will not cause problems and waste too much of your time trying to rebuild what you might lose.

NOTE: Since the release of the late-2008 MacBook and MacBook Pro, it is claimed users are no longer able to create their own bootable CD/DVD. Apple recommends using their own OS X installation DVD, or purchase Disk Warrior or other approved third-party repair tool. However, now that OS X is free, this restriction has been lifted.


  • Got any other applications running? Try switching to these applications and saving whatever you are doing. Then quit the applications. To switch between applications, try Command+Tab.
  • Has the current application froze and can't access your other applications? Try holding down Shift-Option-Command-ESC and keep it there until the application quits.

    Are you in the Finder and can observe the spinning beach ball cursor on the screen? Either the Finder has crashed or is waiting for something that never eventuates, or another application is doing the same thing. Try to Force Quit the Finder: Using the fabled three-finger salute, press the Option+Command+ESC keys simultaneously. A dialog box will hopefully appear showing you the list of all avalable processes running in memory. Select Finder and click the Force Quit button. The Finder should automatically relaunch after it has quit. Once you have control, switch to your other applications and save whatever you are doing.

    If you don't have control of anything after quitting the Finder, try to Force Quit all other visible processes in the dialog box generated by other applications.

    As soon as you have some control of the Finder, backup critical files now in case a more serious problem exists. Do not replace existing files on the backup disk. Backup the files to a separate blank backup disk.

  • The above steps still don't work? Try logging out of your account in OS X. It is claimed this forces cache files to be updated correctly and minimises corruption to these files. After log out, you may wish to consider clicking the restart button on the login window, or take the risk of reentering your password and try again.
  • Log out and log in still doesn't work? It is time to perform a forced restart. Performing a force restart for older computers involves turning off your computer and pressing a dedicated reset button on your Mac. On newer computers (including the Intel variety), while the computer is running, press the Power On button for 5 seconds until the machine turns off. Let go of the button and press it again to turn it on. You should get back to the desktop/Finder.

    NOTE 1: You can also try the Ctrl+Command+Power Button combination.

    NOTE 2: Try disconnecting all FireWire devices from your computer as this could remove the hang up if a process is waiting on something from an external device.

  • Still doesn't work after restarting? Shutdown the computer and make sure the RAM card is seated properly and is working. Otherwise, it is possible you have an "invalid node structure" error on your OS X disk. For this type of error, be prepared to have an alternative startup disk ready from which to boot as this will help you to completely bypass the old OS X and disk you are running and any problems associated with it. Get yourself Disk Warrior and repair the offending OS X and disk problem. Otherwise backup critical files you can salvage and reinitialise the offending disk. Then put on a fresh copy of OS X (or use Apple's own DVD to reinstall OS X plus all the time-wasting work of updating OS X to a stable version) and copy your applications and data files from a backup disk. Problem solved.

    NOTE 1: An "invalid node structure" error is usually the result of a power failure or unexpected shutdown or sleep in the middle of OS X updating critical directory file(s). Rarely it is a faulty hard drive. But if the hard drive is more than 5 years old and this situation is happening even with full power going to the computer, you should consider getting a new drive. To minimise power failure or other issues, make sure the battery on your laptop has sufficient charge. When you have finished with your computer, don't put it to sleep as a small percentage of computers have been known to automatically wake up (hopefully the latest 2009 and newer models should have solved this issue). Shut it down properly.

    NOTE 2: Sign of an "invalid node structure" error include a slowing down of OS X as if booting up, logging on, and launching applications takes an extraordinarily long time. Backup all critical personal files (making sure they are intact before replacing old versions). Run Disk Utility and use the Disk Verify feature. If it finds the error, you can try running Disk Repair option and see what happens. If it fixes the problem, it was probably a power failure issue at a crucial time when OS X was trying to update files. But if not, you could try Disk Warrior. Failing that, you would be wise to replace the hard disk.

    NOTE 3: Do a disk verification of your hard disk and, after repairing any disk problems successfully, do a file permissions check of the OS X files every couple of months to make sure it is okay and especially after installing new software or updates. Or simply learn to avoid having to constantly update your software (a problem when software companies like Adobe Inc. want you to upgrade regularly at a hefty price.). Please note that file permission checks performed by Apple's Disk Utility do not cover the Users folder at the root level of your hard disk. A separate utility will be needed for this. Or get cracking into learning the wonderful world of UNIX commands for manipulating file permissions (not your cup of tea we hear? Maybe Apple should have completed the job properly with Disk Utility years ago).

    NOTE 4: Don't always rely on the SMART technology for determining whether your hard drive is failing. As CNET reported:

    "Tools like Disk Utility's volume verification and SMART reporting are supposed to find problems, but there are times when small errors can go undetected and result in a drive that appears healthy to the software but is just beginning to fail.

    The easiest way to test whether this is happening is to clone the drive and boot off the clone.

    Using utilities such as Carbon Copy Cloner, Drive Genius, or SuperDuper, among others, do a block-level clone of the internal drive to a USB or FireWire drive and then restart the system and boot to that drive. The block-level clone should ensure that the filesystem and partition structure remain intact, allowing you to better assess hardware-related problems." (Kessler, Topher. Intermittent freezes could be a failing hard drive: CNET News. 27 August 2010.)

    Disk Warrior is likely to have more options for detecting a possible failure of the hard drive. Beyond that, a different hard drive will likely reveal the true situation.

    For further information about the signs of when a hard drive is close to failing, read this CNET article.

  • After performing the above steps, we hope this should be enough to bring some stability to your Macintosh computer. However, sometimes you may discover your computer is displaying an unusual number of system errors than usual. Or something is clearly not right but you just can't put your finger (or cursor) on it. If this is the case (should be very unusual for OS X, or what's the point of moving away from OS9 if it isn't?), the following steps below may be helpful.


  • Before doing any repairs or tune-up of your system software, you should always backup your data. We cannot recommend this strongly enough. Backing up your data has to be the single most critical thing anyone can do (and you don't need to be an IT expert to know this). Because if you muck around with your system software trying to fix something (or nowadays you don't have to as OS X is still unstable enough to corrupt caches files on its own if the conditions aren't ideal), you may find yourself unable to boot up the next time you turn on your computer or, much worse, you could lose everything. Always be safe and backup at least your most critical data (i.e. your personal data files and critical databases you use).

    If your Macintosh computer happens to have a hard disk capacity of say around 20GB or thereabouts (virtually unheard of these days), three or four DVD-RW or DVD-R disks should be enough to backup everything. If you have one of those 80GB-320GB (now it is over 1.5TB) hard disks, this is impractical except for storing your most critical files (usually your personal stuff). If you must rely on DVD-RW or DVD-R for backup, you can only keep a copy of your personal stuff. Everything else such as your applications can be reinstalled from the original installation disks.

    However, like most experts, reinstalling applications and updating them again is not exactly a great way to spend a Sunday afternoon. And not exactly the sort of thing you need to be doing in the middle of a business meeting. It is time-consuming, messy to reorganise again, and takes up unnecessary hard disk space with tutorials, movies, help files, manuals and the works. You are better off purchasing a backup disk of at least the same capacity as your own hard disk and backup the whole lot for pure speed and convenience. For example, if you have a 40GB hard disk, purchase a quality external backup disk of at least 40GB for it. If its 120GB, get a backup disk of 120GB or more.

    Generally if you can afford to buy a backup disk with greater capacity than your current hard disk size, then purchase it. Or better still, get the same capacity but pay extra for quality features and manufacturing (e.g. dust-proof, shock-proof, great portability, fast data transfer rate, excellent security features etc). If you value the data on your hard disk, it is better to go for quality of the same capacity as your hard disk than a mediocre unit having a ridiculously high capacity rate.

    For a software tool to do the backing up of your data and applications, there are many to choose from. Our recommendation would be to use the software provided by your third-party drive manufacturer. Or else try Carbon Copy Cloner 3.0.1.

    Don't rely on Apple's Time Machine to do the job. Steve Jobs doesn't like people backing up the entire OS X. And to make sure of it, Time Machine will not do a proper job of backing up all files including OS X. The tool is only useful for backing up the data files you create with applications. Get a more reliable and complete backup tool from a third-party developer to do the job properly. And make sure the tool can do a block-level clone of one disk to another.

    NOTE: Can't eject an external drive? Make sure all running applications are quit. Occasionally after quitting all applications the external drive may still not eject. If this happens, it is usually because a background application has saved and is keeping open an invisible file on the external drive. The best option is to log out or restart the computer. To find out the name of the offending background application preventing you from ejecting, type in the terminal:

    lsof /Volumes/[VOLUMENAME]

    where [VOLUMENAME] is the name of the disk that appears on the desktop when the external drive is connected.

    As a final suggestion, try disabling the indexing feature of Spotlight.


  • One of the most powerful weapons available to you when dealing with any OS X problem is the ability to switch disks and boot off another startup disk so long as you have a big enough hard drive space to do it. This alternative startup disk could be Apple's own OS X installation DVD, or it could be a backup OS X (with no extra third-party applications, plug-ins etc) stored on another partition of your hard disk. The beauty of this approach is that you can instantly see whether a good clean OS X version is behaving well compared to the primary startup disk you normally use but you feel is not behaving as it should.
  • ## A USEFUL TIP ##

    It is an excellent idea to partition the hard disk of your computer into a minimum of 20GB each. The advantage of doing so is that you can install multiple OS X system folders (the minimum should be 2, or 3 if you want to run an older version of OS X such as Panther for greater compatibility with a range of OS X applications). And if you need to run Linux or other foreign operating systems, you can simply erase one or more spare partitions into a suitable format without affecting the data on other partitions. But remember one thing: partitioning a hard disk involves destroying all the data stored on it So before you attempt this delicate and destructive operation, make sure you backup all your data to an external hard drive or burn onto DVD disks, whichever is easiest and most effective.

    Now when it comes to choosing the startup disk to boot off, you do have the option of double-clicking on the Startup Disk Preference Pane and selecting the boot disk you want. But you also have another option.

    To switch between OS X system folders during the boot sequence, restart your machine and press the Option key. The screen will change to a blue colour (this is definitely not the blue screen of death seen on PCs) showing you icons of all bootable OS X hard disks. Click the hard disk icon you want and click the Continue button. Easy, isn't it!


  • Do you have multiple System X folders at the root level of your startup disk? Well, don't! Like the company itself, OS X prefers to be the only OS running on the current startup drive. You can only fool OS X in having additional OS X folders if they are installed on separate partitions of your hard disk. Otherwise, on the same partition, you would be wise to delete the extra OS X folders.
  • Perform a thorough virus check of all the files on your HD, including the system software. You need to do this first before tinkering with the innards of your system software. Otherwise a virus could be lurking around somewhere and this could corrupt any files you try to fix. When doing this job properly, use a CD (or non-writable) Emergency Startup Disk. The disk should contain the latest anti-virus program to help you clean your hard disk. McAfree's VirusScan, Symantec AntiVirus, Sophos Anti-virus (now freeware) or other virus detection program is fine. Just make sure the virus definitions file is the very latest version to be most effective to you.

    Also bear in mind that Apple, Inc. has also developed its own take of an anti-virus protection system called XProtect, available since OS X 10.6 "Snow Leopard". To keep the XProtect malware file definitions updated to the latest version, run the following Terminal command:

    sudo /usr/libexec/XProtectUpdater

    All you need to supply is your admin password. The definitions file will be updated direct from Apple servers.

    For more advanced users, it should be noted that this file should get updated every 24 hours. But if you want to shorten or lengthen the time for the next update, open the following plist file using a text editor:


    and change 86400 (the number of seconds in 24 hours) to a smaller or bigger number:

    <?xml version=”1.0″ encoding=”UTF-8″?>
    <!DOCTYPE plist PUBLIC “-//Apple//DTD PLIST 1.0//EN” “”>
    <plist version=”1.0″>

    The XProtect definitions file is stored on your computer at the following location:


    And if you ever need to disable XProtect, run the following Terminal command:

    sudo launchctl unload -w /System/Library/LaunchDaemons/

    Or to enable XProtect:

    sudo launchctl unload -w /System/Library/LaunchDaemons/

    And to force an update of the virus and malware definitions file by XProtect, type the following:

    sudo /usr/libexec/XProtectUpdater

    NOTE: Disable "Automatically update safe downloads list" in the Security system preference. While this helps XProtect to automatically download and update the definitions file, it can also allow a heap of other files you accidentally download to automatically open up and launch installers. This is half the problem of why a Macintosh can get infected with viruses. It is better for you to decide which applications to launch and when from only trusted sources.

  • If this hasn't helped, we recommend you restart the machine in Safe Mode. To enter Safe Boot mode, press the Shift key down on powering up and immediately after the startup chime is heard until the words "Safe Boot" appear. Actually, entering into Safe Mode will automatically activate the Disk Utility to check for file permission problems and tell OS X to move to the Trash a large number of cache files.

    NOTE: You can run applications in "Safe Mode" (without plug-ins and extensions). This is useful if you want to see whether an application is misbehaving in a new OS environment because of an incompatible plug-in. For what may be the easiest and possibly best way of determining if a plug-in is causing you problems, type the following Terminal commands (Press return after the end of each line):

    cd /Applications/[Application Name].app/Contents/MacOS/

    ./[Application Name]-bin -safe-mode

    where [Application Name] is a name like Firefox or Photoshop.

    If you notice the problems have disappeared, it is likely a faulty plug-in is the culprit. Try removing third-party plugins from within the /Library/Internet Plug-Ins/ or ~/Library/Application Support/[Application Name]/(profile)/Extensions/ folders, or use the application's uninstaller utility.

  • The next useful task to perform is an integrity check of your hard disk and files. In OS X, this means checking for volume structure, catalogs, boot blocks and other directory information for possible damage.

    When performing this task, it is recommended that you boot from another OS X disk (either the original Apple OS X installation DVD/CD or a backup OS X on a separate partition or external drive. Run the Disk Utility of this other OS X and check (and where necessary) repair the drive you suspect there could be problems.

    NOTE: Should you receive a message saying Disk Utility cannot repair permissions because "No valid packages" were found, this cryptic message means you have moved or deleted the BaseSystem.pkg from /Library/Receipts. Apple wants to know you have a legitimate copy of OS X, so get a copy of this package from another OS X and place it in the correct folder, or reinstall OS X from your Apple OS installation DVD.

    To check the integrity of your hard disk and files thoroughly, we recommend using either MicroMat TechTool Deluxe 4.0, or Alsoft Disk Warrior 4.0 or higher.

    If you are unable to check the drive from an external OS X disk:

    1. Restart your computer.
    2. As soon as you hear the startup chime, press the Command (Apple) key and "s" keys simultaneously. You will boot up in single user mode.
    3. At some point you will reach the command prompt where you can type fsck -fy (entirely in lower case letters).
    4. Press the Return key. It will do an integrity check of your hard disk's directory information.
    5. If you find errors, type fsck -fyand press the Return key again and keep repeating until there are no errors. In the rare circumstance where you find unfixable errors, this is when you need the third-party disk repair tools mentioned above.
    6. When finished, type exit and press the Return key. Wait for a moment as it prepares to run OS X.

    NOTE: Checking and repairing directory damage is considered crucial for installing Apple firmware updates on Mac Intel machines. Otherwise the updates will not work.

  • Another common source of problems is in the profusion of (mainly third-party) OS X extension files and startup items.

    Startup items are located in /Library/Startupitems. Use a utility such as Diablotin (the equivalent to Extensions Manager in OS9) to turn off selected startup items. Also comes in particularly handy for controlling Contextual Menu Items, Fonts, Internet Plug-ins, Menu Extras, Preference Panes, QuickTime, Screen Savers, Sounds as well. But remember, turning off the wrong component could result in a non-booting OS X on restart. Make sure you have a "backup" OS X disk to access the contents of your computer's hard drive to help you fix the problem.

    As for OS X extensions (Apple kernel and third-party ones), you may be able to check which kernel extension or other item fails to load up properly because of some kind of software conflict or corruption issue. When you get the chance to re-boot your Mac, press the Command and V keys simultaneously and immediately after the chime. Your computer will boot into OS X verbose mode. Look carefully at the startup console message. If you see the words "error", "failed" or "terminated" next to a software component, you know this specific component has not loaded up. Write down the name of the component and do a search using Spotlight to locate it the next time you reboot OS X in normal mode. If the error message appears next to a cache file, it is time to clear the caches using a freeware tool called OnyX or Deeper.


  • It is highly recommended for old hard drives (at least two years old) to check for block errors (or bad blocks). Block errors are spots on the hard disk where, for whatever reason, it cannot record a zero (0) or one (1) data. Hence when the computer checks by reading it again, it will see the output does not match the input and so generates an input/output (I/O) error. It is usually caused by an unstable physical connection to the hard disk inside the computer or when an external volume is not plugged into the USB or FireWire port properly.

    Sometimes a block error can be nothing more than a file permission problem requiring a fix, or to remove the extended file attributes so a file can be written and read properly on a disk. But in most cases, it is simply a worn spot on the disk.

    If a block error appears, "Error -36" will be displayed. To determine the severity of the error, try to repair file permissions using Disk Utility. Next, remove the extended file attributes by launching Terminal, typing "xattr - d" followed by a single space, and drag and drop the file you are trying to access on the disk just before the error appeared onto the Terminal window. The path to the file will be automatically entered. Press the "Return" key to run the command.

    If the above techniques don't work, Disk Utility can help you to test for block errors. TechTool Pro will actually attempt to repair the errors where possible. But if any block errors cannot be repaired, this may be the time to buy a new hard drive. In which case, backup everything you have on the old hard drive. Try to reformat the disk. If the block error persists, the reformatting of the disk should fail. This is the time to replace the hard disk with a brand new one.

    NOTE: Checking for block errors should be done on older drives before checking and repairing volume structure, boot blocks and other directory information.

    Source: Kessler, Topher. Possibilities for overcoming Finder Error -36 in OS X: CNET News. 20 July 2010.


  • The next useful task to perform is an integrity check of your files in terms of their permission rights.

    This is something you should keep in mind with OS X. Many OS X problems can often be resolved simply by repairing permissions. This is because so many third-party applications and Apple-specific software rely heavily on the thousands of files making up the core OS X system files to perform common tasks and any incorrect permissions could prevent a critical OS X file from accepting say a command from another software to print a page, launch the right application, display files on the desktop (folder), save a file or whatever.

    Repairing permissions should be done before and again after every installation of new software. And if not installing software, check permissions every month or so (more often if running the older Jaguar or original 10.1.x OS X versions). We recommend this should be done by starting up from another OS X disk (e.g. Apple's OS X DVD disk) and checking the permissions of files through your original startup OS X disk.

    Why you must repair permissions? This is best explained through a quote from a MacFixIt reader:

    "...repairing [permissions] is as much as a security fix as a problem fix. Incorrect permissions can lead to programs and files being overwritten, added, linked, etc, without the need for authentication. This can easily then cause the installation of a virus or other software to take control of your system." ( Repairing Permissions and assumptions. 17 April 2006.)

    In essence, it helps to tell your software programs how to handle files and folder information correctly for better security and minimise application errors. If you ever need to know the files touched by Disk Utility, try typing in the Terminal:

    sudo fs_usage 1407, 1408 > fileusage

    where 1407 and 1408 are the process ID numbers for DiskManagementTool and Disk Utility respectively.

    NOTE: A permission in OS X is essentially a piece of additional information called a flag held in every file, application and folder on your computer. It is used to help determine whether the item is visible and accessible to users (in multiuser mode or on the network), the System (OS X) or to specific applications. The flag may contain a unique ID number to identify the application, and additional information to tell how users can access and use it (e.g. whether it is shareable to users on the network, can allow users to read and write files, can allow users to modify files etc).

    Just one tiny permission quirk of OS X you may wish to be aware of. It concerns folders residing on a disk formatted in the standard HFS (the old classic format) will not be shared. This was done by Apple to ensure OS X applications and files cannot be easily shared with really old Macintosh classic computers below OS8.1 and vice versa. Apple wants to give people an incentive to format the disk in HFS Extended (preferably Journaled) format which means upgrading to MacOS 8.1 or higher which in turn requires newer computers to run the newer OS.

    Want to know if you have formatted your disk in HFS Extended format? Choose Get Info from the Finder for your disk and if it says "Format: Mac OS Extended", then you should be okay to share folders.

    NOTE 2: If you intend to manually modify permissions on specific files and folder using a utility such as batchmod 1.3.4, be very careful. You have to know exactly what you are doing. For example, if you accidentally change the permissions on say the root drive incorrectly, you may not be able to start up OS X the next time you reboot (i.e. the Apple logo will probably jump down 5 millimetres from the centre, freeze and the rotating circular coloured pinwheel icon will never appear. If this ever happens to you, get out your OS X installation disk, boot off the CD, run Disk Utility, and click the Repair Permissions button (i.e. all files will have to be repaired). In other words, OS X in its current form (Tiger 10.4.10) does not automatically check for this during startup unless you manually tell it to run Disk Utility and check the permissions.

    NOTE 3: Another classic example of poor built-in integrity checking in OS X (for all versions up to Tiger 10.4.10) is when the invisible.DS_Store files created by the Finder in every folder opened by a user can become corrupted. When this happens, the Finder will crash more often. It will crash when you enter a folder with a corrupt.DS_Store file or attempt to launch and use a file within the folder. The invisible.DS_Store files are designed to associate invisible custom icon files to the folder in which the files reside or to other files within the folder, determine how files and folders should appear when the folder is opened, set the file type and creator code for some files to help the Finder associate the files with the right application, and to the background colour of the folder. This is said to be the safer approach according to Apple instead of the OS9 method of storing all this information inside a single invisible file at the root level of your hard disk. Despite this new approach,.DS_Store files can become corrupted and there is nothing in OS X (now Tiger 10.4.10) or in Disk Utility to detect and fix the problem except for you to discover the problem on your own and figure out how to delete the file (assuming this is the cause). We recommend DS_Store Cleaner 1.5.0 for OS X "Tiger" 10.4.9 or earlier as the preferred and easiest utility for deleting the invisible files (simply drag-and-drop the offending folder onto the application). Or try AppleOff 1.2.4 and set the folders you want this utility to clean the files. The latest OnyX will also remove.DS_Store files. Want to remove all.DS_Store files from every mounted disk on the desktop through your Mac? Type in the Terminal:

    sudo find / -type f -name.DS_Store -exec rm {} ;

    NOTE 4: To prevent the Finder from creating.DS_Store files on remote file servers:

    1. Open the Terminal.
    2. Type defaults write DSDontWriteNetworkStores true.
    3. Press the Return key.
    4. Restart the computer.

    This terminal command will have to be entered for all other Macs accessing the network to be effective. Or ask Windows users to switch off the option to observe invisible files to help reduce their level of complaints to Apple users about their OS X.

    NOTE 4: Having trouble installing software through the Software Update function because of an error message saying you don't have access privileges? We suggest you run Disk Utility and repair file permissions. If the problem persists, make sure the file permissions for the folder that stores updater or application packages is readable. Use the Get Info menu command to check ownership and permissions in the /Library/Updates/ folder. It should look like this:

    System: Has Read and Write privileges.

    Admin: Has Read and Write privileges.

    Everyone: Has read privileges only.


  • Try creating a new user account in OS X. If a user is experiencing problems in OS X (including the Administrator) and not in other users, try creating a new user account. What you are effectively doing is forcing OS X applications and the Finder to create new.plist files, fonts, and kernel extensions.

    If this solves the problem, delete the old user account (after retaining any important data you want from it). If this doesn't work, the problem is likely to be in the root ~Library folder for holding.plist files and other temporary or relatively changeable stuff. Check for corrupted.plist files using Alsoft's DiskWarrior 4.0 or some other utility specifically dedicated to this task. Or see the steps below.

    To create a new user account, you should be the administrator. Open the "Accounts" preference pane. If you aren't the administrator, click the padlock to enter your administrator password. Press the "+" (plus) button to create a new account. If you are creating a new Administrator account, create it, then relogin as the new administrator. Then you can delete your old administrator account.

    The rest is pretty straightforward.

    To retain important information from your old user account, check and move as needed data held in the following locations:

    1. The Documents folder
    2. ~/Music/iTunes
    3. ~/Pictures/iPhoto Library
    4. ~/Library/Application Support/AddressBook
    5. ~/Library/Keychains
    6. ~/Library/Mail
    7. ~/Library/Preferences/ (unless you suspect this file is corrupted).

    NOTE: Store these items somewhere and add them to your new user account one at a time just in case the problem lies in one of these files.

    NOTE: Under Tiger 10.4.4, some users may discover the passwords for gaining entry to their user accounts could fail unexpectedly. OS X may claim the users' passwords are incorrect when they are not. Either you must have the original Apple OS X installation DVD to reset the password (we hope this isn't Apple's way of getting people to buy the latest OS X from the company), or ask the administrator to supply you with the utility to do this. The utility is called NetInfo Manager. If you are the administrator, you will find this utility installed in ~/Applications/Utilities/. Or find a utility to help preserve or protect the NetInfo database from corruption. When creating a new password, avoid using special characters like em-dashes or underscores(_).

    Alternatively, log in as root and change the password of a user's account. You do this by opening NetInfo Manager and selecting the Security menu. Log out of your user account, log back in. However, this time use "root" as the username and the password you specified. Go to the "Accounts" preference pane and modify the desired password. Now you should be able to re-login to the user account.

    NOTE: You can startup OS X in single user mode by press Command and S simultaneously.


  • Everything okay up to this point but still have an error? Alright. It is time to do some spring-cleaning. This is especially true of OS X because preferences files written in XML can become corrupted (all it takes is for an application or OS to be updated and it may not be able to handle the way the information has been organised in their corresponding outdated preference files unless the files have been cleared), caches and log files expand dramatically in file size and may contain unexpected errors, and some other files may need to be updated with new information to ensure smooth and high performance running of OS X.

    One of the most likely sources of corrupted preference information is in Finder's own preference file located at ~/Library/Preferences/

    We shall begin by testing for corrupt preference files. Open the Terminal utility in /Applications/Utility. Type the following:

    sudo plutil -s ~/Library/Preferences/*.plist

    Press the Enter key. Provide your administrator password. The Preference Utility of OS X will be run, checking for errors in your preference files (in OS X, the file names for preferences end with a.plist).

    If you want to check the preference files in the top level system folder, type:

    sudo plutil -s /Library/Preferences/*.plist

    For those not apt to a little programming within Terminal, download and run the freeware from Jonathan Nathan called Preferential Treatment. The utility is slower but it makes the task of moving or trashing corrupted preference files easy.

    Or download our clickable Terminal file for checking corrupt preferences which automatically runs the above Unix commands (works with OS X "Tiger").

    How do you know for sure when a preference file is corrupted? When you see odd behaviour in your applications such as crashes, the ethernet connection dropping out unexpectedly and strange-looking menus, this is the time to clean up the preference files. Remember, preference files are there to help you store your preferred settings for all your applications. For example, setting a default font for Microsoft Word documents is stored in a preference file.

    NOTE 1: We recommend that you back up your hard drive after installing an application so that when a corrupted preference file is found, you can simply replace the bad file with a clean back up copy of the file. This avoids having to re-enter your registration details for some applications that store this information in the preference files.

    NOTE 2: Preferences files store information as text or binary format. Binary format is unreadable for average users and is the preferred format for Apple when creating preference files for Apple applications. To make binary format preference files readable and editable, install the Apple Developer software in the Xcode Tools former on the Tiger OS X DVD. There should be a folder named Developer at the root level of the hard drive. Look inside Developer>Applications>Utilities and open Property List Editor (PLE). This is the Apple tool for reading preference files of any format. Better still, try the third-party utilities Pref Setter and PlistEdit Pro for alternatives. You would only edit a preference file manually if you want to set a value beyond the normal range provided by the application or to insert hidden settings.

    NOTE 3: To find all.plist files associated with an application, use the tool AppZapper. Alternatively, look at the file name of the preference file &151 sometimes the name might indicate the name of the application associated with it. If you are experiencing a problem with an application, try deleting the application's corresponding preference file and see whether the problem persists.

  • Next thing to do is clear caches files. Cache files are temporary places for holding data for OS X and other applications in order to help them run faster. The files tend to hold commonly-used graphics, contents of dynamic menus, and frequently-used calculations. Caches are often used to speed up launch times for applications and while doing intensive repetitive work within an application. However, on the rare occasion, the cache files can grow very large or may contain an error which could create application oddities.

    To clear cache files (you should be the administrator), you need to find their location. In OS X, this is /System/Library/Caches; in your user folder's Library folder; and within individual application folders. The process of clearing caches for OS X can be achieved with the help of a freeware utility called OnyX from the French company called Titanium. Use only OnyX 1.5.2 for Panther and 1.8.4 for Tiger (the final versions), and Onyx 1.9.0 for Leopard. Use the latest version 2.2.7 for Snow Leopard users. For all other cache files, it is time for a manual "seek and destroy" mission. The most important caches to clear, especially between major updates and upgrades of the OS, are the kernel extension caches and font caches.

    If you have to do this manually, delete the following caches: (a folder in /System/Library/Caches)

    Extensions.kextcache (a file in /System/Library)

    Extensions.mkext (a file in /System/Library/) (a folder in /Library/Caches/)

    Files that start with (in /Library/Caches)

    You will be asked for your administrator password when moving these files to the trash.

    How do you know for sure when a cache file is corrupted? Usually it is hard to tell. But if the cache file is sufficiently corrupted in many places or corrupted in a critical place, you will see odd behaviour in your applications such as your custom preferences not loading up properly, sluggish performance of OS X and other applications, or menus having strange characters appearing on the screen. When this happens, this is a good time to clean up the cache files.

    After clearing caches, it is wise to restart the computer.

  • Follow this cache file cleaning regime with a good deleting of log files. Log files are now being created and populated with information on a regular basis within OS X because hard drive capacities have increased significantly to the point where software companies such as Apple and Adobe Systems, Inc., can record what's on your hard drive, who logs onto your machine, what time you've logged on successfully or unsuccessfully, which applications you use, what you do with the applications, and any errors or problems you encounter when using the software. The logs are related primarily to the applications you use and how you use them and records everything from the mundane to the most important details.

    So, in essence, if you do something you shouldn't, it may now be possible for certain individuals in law enforcement to deduce what you were doing and with what software and use the log files as possible evidence in a court of law should an authority decide to inspect your computer. On the positive side, if you do the right thing, it can help software companies provide better software, including more features and less bugs for you to enjoy (well, that's the theory of it).

    Think of log files as a double-edged sword. It can work for you, or it can work against you.

    The biggest drawback with log files, apart from the obvious privacy concerns and the possibility someone could devise a trojan to retrieve log files in specific "common" places and send them over the Internet, is that they can grow to phenomenally large sizes. If you are a bit short of hard disk space, log files are a good place to do your spring-cleaning work.

    To keep users busy locating them, logs files are stored in several different places. At the system-level, this will be in System/Library/var/log/ and Library/Logs folders. Also check your Users folder in ~/Library/Logs/. Use Console to highlight and delete logs listed in your Users folder. Use the Command-Delete key to set your action. The log files will disappear.

    For system-level logs, try the freeware utility called OnyX to delete them automatically. Also if you see odd-looking or missing icons in the Finder buttons (such as the navigation buttons in the windows), use OnyX to clear caches and restart.

  • Next, run the Keychain Utility in the Utilities folder in Applications. There should be a menu command called Keychain First Aid. Click the Start button and let it verify and repair any problems it finds. Follow this with a file permissions check using Disk Utility.

    NOTE: Do not delete the files stored in /System/Library/Keychains/, or you will get a warning message of "Safari can't verify the certificate...". Even when you click the check box to trust the certificate, it will not work. If you lose these files, get a copy from another OS X disk (or painfully reinstall OS X). You must have the following files in the folder: EVRoots.plist, SystemCACertificates.keychain, SystemRootCertificates.keychain, SystemTrustSettings.plist and X509Anchors.

  • To automate these spring-cleaning tasks, we recommend a freeware utility called OnyX. This utility will also do scheduled maintenance work of OS X at specified times, taking the drudgery out of most cleaning work.

    Apple also provides some of its own automated maintenance scripts in Unix for running under the command line via the Terminal utility. Terminal is located in /Applications/Utilities.

    NOTE: To clean up duplicate entries in the Open With... contextual menu command for Tiger OS X 10.4.x and higher users, run this command via the Terminal utility:

    LaunchServices.framework/Versions/Current/Support/ lsregister -kill -r -domain system -domain local -domain user

  • Another source of incompatibility are third-party input manager plug-ins (called haxies) found in the ~/Library/InputManagers/ folder. Try removing the plug-ins and see whether the problem persists. The same should be done to ~/Library/Contextual Menu Items/ and ~/Library/Internet Plug-Ins/ folders by removing third-party plug-ins.
  • Now we must update some files. One important technique to implement is a thing called prebind. Prebinding in OS X means figuring out the code to be used for an application when launching it. It's about updating information in a database file needed by applications to know where certain libraries and special codes in OS X are held. In pre-10.3 versions of OS X, binding information was not strict and therefore rarely updated properly. This is the reason why a number applications had extremely slow launch times. But by having the information updated properly, applications can launch and run more quickly.

    To update the prebinding information, go into Terminal and type:

    sudo update _prebinding -root /

    and enter your administrator password.

    Or if you have a prebinding error and want to know why, you may wish to type the following:

    sudo update _prebinding -root / - force -debug

    For those curious readers wanting to know the list of dynamic libraries that are prebound, OS X keeps a record of the list in the following text file:


    Just one word of warning: updating the prebinding information can potentially take up to an hour depending on how many applications are installed. We recommend you do this at the end of the day, perhaps once a week or as you feel the applications are getting a little sluggish. Under Tiger, you should only have to do this once after an application install. And never try to interrupt the process (e.g. opening an application, surfing the net, playing games and so on).

    For a clickable Terminal file, download Prebinding.hqx.

    NOTE: OS X has a set of Unix maintenance scripts for maintaining your files in good order. The scripts are run on a daily, weekly and monthly basis as indicated by the times set by Apple Inc. (formerly Apple Computer, Inc.). The actual times are: (i) daily - 3.15am; (ii) weekly - Saturdays 4.30am; and (iii) monthly - 5.30am on the first day of the month. For most users, this may not be convenient as most computers are switched off during these times. The maintenance scripts can be run at any time by downloading and running a utility called MacJanitor from Brian Hill. If you want to reschedule the maintenance scripts, use a utility such as the freeware CronniX.

  • Another updating technique worth considering is a check for updates to various plug-ins, QuickTime components and third-party software you have installed. In the latest Tiger upgrade, Apple has made substantial changes to the file format (similar to the upgrade from HFS to HFS+ in the Classic Environment) to the point where some applications may no longer work (including the Finder). So be prepared to do lots of updating or upgrading of your third-party software (with OS X version 10.4.10 already out, hopefully this updating work should be the least of your worries). And if you are updating the OS, consider re-applying the update using the full Combo updater from Apple and restart your computer.

    NOTE 1: Problems with the network in Tiger can be resolved by removing spaces in the Computer's name and keeping the name short in length. Also turn off IPv6 configuration option if you find after the update to OS X 10.4.5 that the network connection, uploading and downloading files, the internet are all slow or your computer is spontaneously disconnecting from a network for no apparent reason. To achieve this, go into Network system preference pane, clip on TCP/IP settings, click "Configure IPv6..." button, and click the "Off" button. Press the Apply Now button to complete the work and force OS X to remember the setting (until probably the next OS X update is released by Apple).

    NOTE 2: Problems with AirPort connection under OS X 10.4.5 such as spontaneous disconnects; or not automatically reconnecting after waking from sleep, starting up or first turning on the AirPort card? Try deleting the AirPort keychain entry:

    1. Launch the Keychain Access application located in /Application/Utilities.
    2. Move to the "System" set of keychains in the top left corner.
    3. Delete keychain entries referring to AirPort.
    4. Re-establish connection to the AirPort and re-enter authentication information.

    Next, consider changing the channel of the Wi-Fi for the device you are having trouble connecting in case someone else in the neighbourhood is transmitting and receiving on the same channel. As one MacFixIt reader suggested:

    "Don't be too quick to blame your own system or apple software. Run iStumbler to see if any of your neighbours are running on the same wireless channel. For me, it shows 6 of the 15 nearby nodes are using channel 11, four are using channel 6, and most of the rest are on different channels. If you set your system to use a channel your neighbours are not using, you may find your connection much more reliable. If there isn't a free channel, choose the channel showing the weakest signal. If you start to notice problems and you have not changed your set-up, it possibly means you have a neighbour with new hardware on your channel." (Kessler, Topher. Fixing AirPort problems in OS X: CNET News. 7 October 2011.)

    If all else fails, turn off and on the AirPort, turn off "IP over FireWire" option in the Network preference pane. And consider turning off IPv6 in the Network preference pane.

    Removing FireWire devices from your computer may also help to resolve AirPort connection problems as there may be RF interference between the FireWire devices and the wireless AirPort module inside your computer. As MacFixIt reader Mark Donohue has allegedly discovered:

    "I have lots of Macs (5) on a mostly wireless network. AEBS (gigabit n) + recent purchase of Airport Express n to extend the network. Leopard 10.5.2. All Airports at latest software and firmware versions. IP6 turned off (according to your own previous suggestions). I could not understand the intermittent loss of links to the internet by my MacBook Pro (latest version, 7200 rpm disk, 4 GB RAM).

    Until this morning.

    I was downloading the new update of MailSteward (v8) in the vicinity of the Airport Express when I plugged in my external FireWire drive 2 seconds before the download finished. BOOM. NO data transfer (watching iStat Menu - brilliant software from AUSTRALIA!). Eject the disk - still no data transfer. UNPLUG the firewire disk and - BOOM - transfer back to full speed immediately. Did the same with the new Java software update. Same result.

    Used the SAME disk in USB2 mode, no problem. Maybe slight decrease in transfer speed, but not much. Oddly, my other older (Sept 07) MBP is running for my wife booted off an external FireWire drive and does not run into the same problems. The problem may be the new Penryn processor?" ( FireWire devices interfering with wireless connectivity?. 30 April 2008.)

    As a suggestion, try moving the FireWire devices further away from your computer, and/or purchase a higher quality FireWire cable with better RF shielding properties.

    NOTE 3: If you have a MacBook Pro and OS X shows signs of kernel panics every 15 minutes or so (probably an older version of OS X), try turning off Airport. If this works, turn on Airport and connect manually using a fixed IP address. It should work.

    NOTE 4: This MacFixIt article on 10 June 2008 suggests at least one third-party software application could be slowing down AirPort connection speed on Intel-based MacBook Pro. It alleges the culprit could be Real Player (a tool for playing.rm movie files on the Internet). You may wish to try deinstalling (or get an improved update to) this application. As of 14 June 2008, the makers of Real Player have released to Real Player 11 build 884. Hopefully this will work better.

  • Trying to minimise the number of files on OS X is not easy these days. OS X's architecture is designed to split up applications into a folder containing individual resource files. Add to this the help files written in html or xml, clipart and so on, and the number of files for a single application can exceed 10,000. Applications in OS X are also more integrated (e.g. Mail/Safari/QuickTime in OS X, aka Microsoft Explorer in Windows 95) to the point where the removal of some files can stop the applications including OS X from functioning properly (especially if you remove QuickTime under OS X, but shouldn't be a problem under Windows machines).

    The best thing you can do is experiment. Keep a back up of your hard disk, remove some files for which you know their association for particular application(s), and see what happens.

    As a recommendation, if you install third-party applications and want to remove them later, use fseventer 2.2.2 to keep a record of where the files are placed when you do the installation (even existing files that change during installation are logged as well). Use the uninstaller supplied, and be prepared to manually remove them if the uninstallation procedure is not foolproof (e.g. a classic example is the trial version of FileMaker Pro 7-10). Check the following locations where an application may install files:

    Application folder at the root level of the hard disk

    Application Support folder in the User folder

    Preferences folder of both the System and User folders

    Sometimes an application may install files in the invisible folders at the root level of the hard disk.

    AppTrap is a useful utility to help you remove associated files to an application you want removed.

    Or consider Sherlock under OS X "Panther". But don't use Spotlight under OS X version 10.4 (the replacement for Sherlock) as Apple has decided to do away with searching for invisible files (even though it has the criteria to do this if you look carefully).

    And be patient. There are enough files worth throwing away. But the key will be in choosing the right ones.

    NOTE 1: Having trouble trashing some locked files under OS X? Try pressing down the Option key and trash the file. If this still does not work, we recommend using a freebie utility such as Trash It or Super Empty Trash. The only way to go when Apple can't or won't do the job properly for users.

    If the files are not locked but refuses to be trashed for whatever reason, restart the computer — sometimes an application might be using the files. Also do a file permissions repair using Disk Utility after restarting the computer to ensure you have the correct privileges to allow you to delete them. Next, try the Secure Empty Trash command in the File menu of the Finder. There is also the utility called OnyX which does a pretty good job of deleting files in the trash. And if all else fails, boot into another OS (preferably on an external drive) and delete the offending files. But remember, if you get this far, you may need to check the volume you were originally on to make sure there are no disk errors using Disk Utility, or Disk Warrior. The more you work on your files with a disk error, the more likely you will corrupt the disk and make it harder to recover your files.

    NOTE 2: Want to transfer files through the Bluetooth method under OS X "Snow Leopard" 10.6.x? Open the System Preferences. Click the Sharing preference pane. Turn on "Bluetooth Sharing" and choose the folder you want users to access. Make sure you have typed a Computer Name for users to easily see and identify your Bluetooth-enabled Mac. Turn on Bluetooth on your other device (i.e. the users side) and choose "Browse Device...". Click "Search" button. Your Computer Name should appear. Return to the original Mac and click "Allow" when asked "[Bluetooth Device Name] wants to browse your [Folder Name]". The browsing window will appear on the users' bluetooth device. Download files as you require through drag-n-drop using the mouse. For multiple files, we recommend using Disk Utility to create a dmg file or use a compression tool like DropStuff to combine all the files into one. You're done!

  • After simplifying your hard disk, don't worry about rebuilding the desktop files. In OS X, this is no longer necessary. However, if the system problem lies in the Classic Environment (1), do a desktop rebuild in the following manner:

    1. Click the Apple logo in the top left-hand corner of the screen.
    2. Choose System Preferences.
    3. Click the Classic control preference pane.
    4. Select the Advanced tab.
    5. Press the Rebuild Desktop button.
  • Check to see that your applications actually has a proper icon. If it looks generic like it is a Console document and you know it is suppose to be an application, change the filename extension to ".app". Double-click the icon to see if your suspicions have been realised correctly (i.e. it should open as an application).

    It is also a good idea to make sure your hard disk has been formatted as HFS+ and repair your disk if you see this problem.


    OS X in its present form is not capable of self-repair (as of Snow Leopard version 10.6.x). It is still possible to corrupt files during the normal operation of the computer and OS X has nothing check for this. For example, when running a third-party utility such as Cocktail, an invisible file called "sudoers" in the invisible /private/etc/ folder at the root level of the OS X hard disk may suddenly become zero bytes in size. Afterwards you try to run another application such as OnyX where it asks for your administrator password, only to find your password does not work. Apple's Disk Utility can't repair the corrupted file. So you are faced with purchasing Disk Warrior to repair it or reinstall OS X.

    The alternative and cheapest solution is to find another OS X computer, make visible the private folder and copy the sudoers file where you can replace the corrupted file on your own OS X machine. This is easily achieved by booting into OS9 or Windows XP to bypass OS X restrictions in accessing this invisible folder. Or you must use Terminal to enter the appropriate file copy and replacement UNIX commands.

    If you need a copy of sudoers, please click here. Then run Disk Utility to repair the permissions. If you don't repair permissions, you may get a similar message as the following:

    "AppleScript Error

    "sudo: /private/etc/sudoers is mode 0755, should be 0440 (1)"

    Once the permissions are repaired, the problem should be solved.

    This corruption issue appears to be the same in the case of the Keyboard Update 1.1 for Intel iMac mid-2007 models. Users have noticed how F3 for Expose, F4 for Dashboard and the multimedia function keys don't appear to work even after the update is applied. Only a full reinstallation of OS X will fix whatever file corruption has occurred.

    Another ripper of a file corruption problem involves Apple's own Disk Utility. If you have insufficient hard disk space to perform a disk image (.dmg) of a folder, for instance, and you don't realise it, Disk Utility will appear to do its job of creating a disk image. But then it can suddenly finish the job (i.e. reached the end of the available hard disk space) and won't tell you why or what happened. You will see what looks like a successfully completed disk image.

    If you don't have the verify checksum option turned on and forget to open the image file for testing to see if the Disk Utility has done its job properly, then the next time you open it you will notice an "input/output error" message on the screen. But this is the start of your problems. You may be able to recover some of your files in the disk image. But, incredibly, OS X on your startup disk will soon misbehave badly as if icons appear corrupted, certain applications such as Safari won't launch, and a number of files can't be copied because somehow something has overwritten on top of them. Running the Disk Repair and Permissions Check options via Disk Utility won't notice a problem (useless!).

    If you leave it too long, like say 24 hours, the next time you boot up, OS X will get stuck and you'll never get to the desktop (i.e. system files have been corrupted).

    This is the classic sign of file corruption due to poor programming on the part of Apple inside the Disk Utility tool. The only solution you have is back up the remaining good files and reinstall a fresh, new copy of OS X.

    NOTE: Apple has also not updated Disk Utility for Tiger users to ensure bad file permissions are not transferred over to OS X Leopard files. Leopard now uses a new permissions verification technique and Apple makes no apologies for this situation for Tiger users. Either upgrade or learn the hard way if you forget what to do.

    In essence, if you suspect any strange unexpected behaviour not resolved by any of the steps mentioned above, consider the possibility of a file corruption by installing OS X on another partition of your hard disk and running the computer off this system. If the behaviour is non-existent, then you know there is a corrupt file somewhere.

    NOTE: Try applying the full combo update to see if the corruption is resolved before going for the full OS X reinstallation.


    Defragmenting the HD is called optimisation and journaling in OS X. Use the Disk Utility to tell OS X to fully optimise your drive. Enable journaling for limited defragmentation. Otherwise use a full defragmentation tool such as Micromat's TechTool Pro 4.0 or higher. We recommend you do this about once a month.

    NOTE: It is recommended that you only use a third-party deframentation tool if you have lots of large files (sort of in the gigabytes range such as digital movies) and the hard disk space is limited (perhaps 10GB or less). When defraging, always make sure you have a reliable power supply to your computer and you do not interrupt the process by doing other things on your computer. Defragmentation via another tool not from Apple should rarely be used under OS X.


  • Still having trouble with your system software? You should be aware of one thing. OS X needs a lot of memory. Think of OS X as requiring the same amount of memory as Windows XP or NT. Virtual memory is always turned on, so give OS X at least 2GB of hard disk space to run.

    One more thing. If it is a memory problem, use Disk Utility to ensure there are no block errors. And reduce the number of applications you are trying to run simultaneously. In the latest 15-inch and 17-inch unibody MacBook Pro laptops issued after September 2009, you may get extra RAM simply by turning on a separate and faster graphics accelerator chip (i.e. the NVIDIA Ge Force 9600M GT) using the option "Higher performance" in the Energy Saver preference pane. This will unload the more graphics intensive applications such as Adobe Photoshop CS4 and Parallels Desktop 5.0 from the standard system RAM chips onto a separate 512MB or 1GB graphics-dedicated chip. Otherwise purchase more RAM.

    NOTE: Just an interesting discovery: Did you know a slight performance boost to your Mac is possible by installing RAM in matching pairs. In other words, try to get identical RAM sizes and install them into the two memory slots of your computer. It is believed the performance is noticeable. But if you are more interested in writing documents in Word, the extra boost may not be of much use to you. Only useful for gamers and multimedia experts. Try it, especially for Intel-based Macs that use the integrated Intel GMA950 graphics processor. You'll need a minimum of 80MB of RAM to run it and the rest for loading OS X and the applications. Minimum total RAM should be 512MB (i.e. two 256MB RAM cards).


  • The next step is to disconnect all USB and FirWire device(s) from your computer. This is crucial when updating or upgrading OS X. When removing device(s), you don't have to turn off the power. All USB device(s) are fully protected and can be removed at any time with safety (the same thing is true of FireWire devices).

    NOTE 1: The exception to this rule is when your system experiences a complete freeze/crash accompanied by a spinning pinwheel. If this happens, don't disconnect the external drives. If you do, you may solve the freeze problem restoring order to your system. But it is likely you will also experience file corruption on the external storage device. Removing the external drive with power on when the system is stuck in the spinning pinwheel mode can cause corruption.

    NOTE 2: If you experience repeated system freezes, kernel panics and more and your Apple computer is looking new enough not to be the cause of the problems, check to see whether you aren't using a third-party USB device such as a Microsoft USB keyboard plugged into an Intel-based Mac mini or something along those lines. Try to stick to Apple USB devices where possible. Or make sure you have the latest third-party drivers, firmware updates and/or USB devices. For example, MacFixIt reader Cole Armstrong writes:

    "My new Mac mini crashed on me within 24 hours. I did not change any of the stock settings or add any new hardware to the box itself. It was to the point that I could not even re-install the OS. Before it would boot the OS I would get a multiple languages message saying I needed to restart. Every time I booted up and I never got to the OS.

    Apple Tech support could not help me with the matter. So I had to send it back. I received my second mini in the mail a week later. Same configuration: 1.66ghz Core Duo/80gb HD/2gb's RAM. 24 hours later it then crashed...luckily I was able to reinstall the OS, I changed from my brand new OS X compatible Microsoft Keyboard, and bought an Apple Brand Keyboard.

    So, I re-installed the OS without the Microsoft keyboard plugged in. Then I used the Apple Keyboard to complete the install.

    So far my system runs very quickly and smoothly and I am not having running midi programs. The whole system just seems to run a lot better and I get that gut feeling that it is fixed. I have been up and running now for 36 hours with no problems....this is a new record." ( A reminder: Errant USB devices can cause system freezes, other issues. 21 March 2006.)

    NOTE 3: If the Mac mini cannot handle third-party USB devices (because it doesn't come with Apple-specific keyboards, monitors etc), it makes you wonder what's the purpose of a Mac mini? Shouldn't you be able to plug third-party devices to it? Wake up Apple!

    NOTE 4: Does you internet connection drop out several times in a day? Perhaps the ISP's own server could be playing up. Or consider the idea of removing the filter dongle between the phone line and your ADSL modem used to keep the ADSL signal separate from voice signals. Also remove old phones connected to the same line as these may not be compatible.

  • Check the hardware manufacturer's web site for your problematic USB device and download the latest driver update (including firmware).

    NOTE: A special note about firmware updates is that under no circumstances should you be doing anything with your computer while installing a firmware update. There should be absolutely no interruptions. The consequences of not following this advice is the hardware item subject to the update is almost certainly going to become inoperable. Always let the update go through its process to completion. When downloading a firmware update, go for the full standalone update. Restart the computer to ensure no applications other than OS X and the Finder are running. And check System Profiler to determine the firmware version of any device before deciding to update it — accidentally installing an older firmware version could cause problems. Updating firmware is a delicate operation best done by the manufacturer (or Apple). If users are ever asked to do the job, it is very important for manufacturers to provide clear instructions and messages during the installation to tell users exactly how it should be done.

  • If you notice the internal hard disk on your computer suddenly freeze for no apparent reason, or your computer is unable to startup properly because it thinks there is no functioning system software in the internal hard disk, the problem may be that the computer does not notice the existence of the hard disk itself because the hard disk connector is losing contact with the motherboard's hard disk connector (could be a heat problem). Check the Hardware Stability page for information on what to do.

    To check your hard drive for hardware problems, download checking hard drives with SMART technology. Double-click on the uncompressed file to run the Unix commands in Terminal.

  • ## A USEFUL TIP ##

    Having problems with your laptop accidentally turning on when the lid is closed? Do you find your laptop gets very hot when you take it out of your bag? Well, you are not alone. This is a common problem for MacBook Pro laptops (we hope this is the only model to be afflicted by this silly problem). A few aluminium PowerBook G4 laptops have also experienced this issue. The solution? Well, there isn't a foolproof solution for all machines. For most laptops, Glenn Fleishman of has recommended you turn off the lidwake value by typing in the Terminal:

    sudo pmset lidwake 0

    To wake up the laptop, just open the lid and press any key. A much improved solution (if Apple is unable to get the right manufacturing design). If the command doesn't work, try another power management UNIX command instead of lidwake. For a list of possible options, try:

    pmset -g cap

    Occasionally, even after trying this method, other laptops may continue to turn on with the lid closed despite the above recommendation either because something is trying to wake up OS X to do its job, there are faulty settings in the parameter RAM (PRAM), or some kind of hardware problem exists in the lid's latch. As Glenn Fleishman said:

    "It takes a village to put a laptop to sleep....Keith Dawson and me with our recalcitrant laptops [have a problem]. Keith has a new 17-inch MacBook Pro that has several times nearly overheated, according to its three internal temperature sensors, because it woke up after being jostled in his laptop bag. I didn't have the heat problem, but my 15-inch aluminum PowerBook G4 has long had an incontinent latch that makes the computer liable to wake up in my bag." (Fleishman, Glen. Sleepless (and Latchless) in Seattle: Tidbits. November 2006.)

    Or another option is to consider deleting the sleepimage file created by the OS of your RAM contents. If you have set up your laptop to standard sleep mode and still have trouble getting the machine to sleep or wake up, try deleting the sleepimage file is /private/var/vm/sleepimage. It is likely the sleepimage file could be corrupted in some way. Because the /private/ folder is invisible at the root level of your hard disk, you will need a utility to make visible invisible files and folders. Or run the following Terminal command:

    sudo rm /private/var/vm/sleepimage

    Removing the sleepimage file causes no harm to your computer and can potentially help you to reclaim up to 8GB of hard disk space (depending on how much RAM you have available in your computer) for Intel Macs. Furthermore, the passwords you've entered when the computer was awake and stored in the sleepimage file on sleep mode are removed as an improved security measure. To disable the creation of a sleepimage file or enable a more secure version of the sleepimage file using "secure virtual memory", do the following:

    1. Go into the Security preference pane.
    2. Put a tick in the box that says "Use secure virtual memory" and restart your computer.
    3. Change the sleep/hibernation mode of your computer's power management controller (SMC) by running the command in Terminal, sudo pmset -1 hibernatemode x, where x is 5 or 7.

    The number represented by x can also be 0, 1 or 3. The numbers have the following meaning:

    0 - no sleepimage is used, and RAM contents are kept alive.

    1 - only sleepimage is used, and RAM contents are purged.

    3 - RAM is kept alive and a sleepimage is used when power reaches critical levels.

    5 - only sleepimage is used, but with secure virtual memory enabled.

    7 - when power reaches critical levels, both the live RAM and sleepimage options are used but with secure virtual memory enabled.

    Enabling "secure virtual memory" simply means your sleepimage file will be encrypted.

    If all else fails and nothing can put your machine to sleep, consider disconnecting the keyboard. As Topher Kessler of CNET discovered from one of MacFixIt readers:

    "While you might be considering third-party devices, do not overlook the system's keyboard and mouse as well. Recently, MacFixIt reader Kent wrote in with a situation where apparent faults in the Apple keyboard were resulting in the system being triggered out of sleep, which apparently has happened to a few people's Apple keyboards. After using the utility PleaseSleep to keep the system in sleep mode, Kent found in the system logs that one of the keyboard's USB ports was issuing a wake-up command to the system, and if the keyboard was removed then the system would stay in sleep mode properly. In this case, changing the keyboard may be the only way to prevent the issue." (Kessler, Topher. Mac refusing to sleep or refusing to stay in sleep mode: CNET News, 27 September 2011.)

    No doubt disconnecting a keyboard from a laptop will be a bit tricky to do. So disconnect all external devices and hope Apple will provide a firmware and/or OS update to fix the problem for your laptop.


  • Another possible solution to your system software problems is to consider zapping the parameter RAM (PRAM). This stores all the essential information about your computer such as the date and time, speaker volume, cursor flash rate, contrast and colour details of your screen, network details, boot volume information and other useful data which is kept constantly "alive" by the motherboard battery. Occasionally, however, corrupt information can creep into the PRAM and cause instability problems to your system software and hardware-related components and possibly even cause some hardware items and OS X not to be recognised (e.g. you could have problems booting into an OS X volume, or the computer doesn't see the extra RAM or external drive you have installed).

    To zap the PRAM, press Command, Option, P and R at the same time within 5 seconds of startup (i.e. before the screen turns on, and immediately after hearing the startup chime). Make sure the Caps Lock key is not engaged. Keep pressing the keys. The startup sound should repeat itself. Keep pressing the keys until you hear the startup chime sound three or four times. Then release all the keys.

    NOTE 1: Zapping the PRAM means restoring the PRAM settings to its default factory settings. So you may have to later change the settings in System Preferences after zapping the PRAM.


  • And as a final resort (it sounds like things are getting pretty serious at this stage), reinstall the Combo update file for your OS X. If this doesn't work, reinstall the full OS X from the original installation CD (something that Apple encourages a lot), followed by your Combo update file, and finally update your third-party applications.

    On the issue of CD drives, it may be worth noting how some users have experienced trouble ejecting a CD/DVD from the internal optical drive of 17-inch aluminium PowerBook G4 and MacBook Pro laptops. This is usually because the casing has been bent upwards slightly by pressure of the hands resting on the laptops. You will see this at the left of the opening to the CD drive (the weakest part of the casing). On occasions the problem can also be software-related such as an upgrade or update to OS X. If this sounds familiar, try typing in the Terminal:

    drutil tray eject

    Alternatively, restart the computer and on hearing the startup chime, hold down Command Option O F keys (make sure you disable firmware password to access this key function). Next, type:

    eject cd

    Finish with:


    to bring you back to the standard boot sequence for loading OS X.

    If unsuccessful, try shutting down the computer, then press the mouse button/trackpad button and the power button. As the computer boots up, the disk ought to pop right out.

    You final resort is getting an Apple technician to fix the CD/DVD drive or laptop casing.

    Actually, any time you want to upgrade/update OS X or install new software, many problems can be resolved by following these procedures:

    1. BACKUP: Backup your files and test the backup (i.e. have a look at the files, open a few up and see if the files look fine). Never assume you don't have to no matter how good your computer might be. Do it, you'll be glad you did.
    2. QUIT APPLICATIONS: Quit all running applications and processes. You really don't need them to be opened when you are installing. So be patient and let the installer do its thing. As an example, there are likely to be a number of libraries in OS X being shared among different applications. Therefore if an application is not quit before installation, an installer may not be able to update one or more libraries and you could be left wondering why something isn't working as well as it should.
    3. DISCONNECT PERIPHERALS: Disconnect all FireWire and USB peripherals. This includes Wi-Fi and ethernet connections. Don't plug them in until after the first successful reboot following an installation (if it requests that you reboot).
    4. RESTART COMPUTER: Just to be safe, restart your computer.
    5. FIX FILE PERMISSIONS: Boot from the OS X Install CD and run Disk Utility's Repair Disk function (or use a third-party drive utility such as DiskWarrior or TechTool Pro) to fix file permissions and other problems and restart the computer to launch your fully checked and fixed OS X on your hard disk. Alternatively you may wish to boot the computer in Safe Boot mode by pressing the Shift key down on powering up until the words "Safe Boot" appear — the Repair Disk function apparently is automatically activated in Safe Mode for MaxOS X version 10.2 or higher according to this Apple article and may take several minutes to check your directory. We call this clearing up current issues and running general maintenance checks.
    6. INSTALL UPDATES: Install the software you want to add to your hard disk. You can do this in Safe Boot mode or when OS X is booted normally (after file permissions have been fixed). We recommend the full standalone combo update installer if available. Otherwise accept what's given.
    7. FIX FILE PERMISSIONS AGAIN: After rebooting, it is important to run Repair Disk Permissions one more time (considered the most critical step).
    8. CLEAN OUT CACHE FILES (OPTIONAL): It is a good idea to use a freeware utility such as OnyX or Cocktail to clear caches and old log files.
    9. RESTART COMPUTER: Do a final reboot.

    Everything should be okay to this point. But if you have unexpected problems with FireWire devices, make sure they are disconnected and reset the Mac's NVRAM:

    1. Just as the computer is powering up from a shutdown (not from a restart), hold down Command-Option-P-R (make sure you disable firmware password to access this key function) before the screen lights up.
    2. Let the Mac chime twice and let go of the key combination.
    3. Before the screen lights up again, hold down Command-Option-O-F. This will show the Open Firmware screen. NOTE: Does not work with late 2009 iMacs.
    4. Type the following:

      set-defaults [Return key]

      reset-nvram [Return key]

      reset-all [Return key]

    5. After pressing the final Return key at the end of this line, the computer should restart.

      Another option involves (a) resetting the Power Manager; (b) trying the fake "programmer's reset"; and (c) running the Apple Hardware Test CD. But hopefully you should not have to go this far.

    NOTE 1: Use a disk repair utility (we recommend Alsoft DiskWarrior 4.0 or higher, now a universal binary version) first to check for bad sector blocks and other disk problems before reinstalling the system software. And never run software in the background when installing new software except for the installer application only.


  • To assist with tracking down a hardware problem, we recommend using Apple's own Hardware Test for Intel-based Macs:

    1. Disconnect all external devices such as printers and scanners, except the keyboard and mouse.
    2. With the computer shutdown, press the power button. Quickly insert Disk 1: OS X installation DVD (not the Applications Disk 2) and press the "D" key while the screen remains black (and before it turns grey).
    3. The Apple Hardware Test will startup.
    4. Select your preferred language.
    5. Choose whether you want to perform a thorough diagnostic test or not.
    6. Press the Test button, and wait.

    The results of the testing will be displayed in the window in the bottom-right of the console.

    If this doesn't work, it need not necessarily mean there is no hardware problem in your Mac. Talk to Apple for a recommended solution to your problem.

  • A problem with external devices not connecting or showing up on your Mac? Join the club!

    With the advent of the Intel-based Mac and significant changes to OS X "Tiger" 10.4.4-10.4.5 for PowerPC users as well as OS X "Leopard" 10.5.x for Intel users, some people may find mounting FireWire drives, recognising iSight and other hardware issues to be somewhat problematic to say the least. For example, you may not be able to mount a FireWire drive when connected and with power on. A good place to check should be in Network preference pane. Why? Because it may be possible OS X is trying to use the FireWire port as a network port. We recommend turning off this network capability through FireWire ports by:

    1. Opening the Network preference pane.
    2. From the "Show" pop-up menu list, select "Network Port configurations".
    3. Uncheck "Built-in FireWire".
    4. Click the "Apply Now" button.

    If all else fails, shutdown the computer, turn off power to all FireWire devices, disconnect them for at least 10 minutes, and then try reconnecting and turning on your computer.

  • Having trouble with your USB devices. Well, let's see. Would you happen to be using an Intel-based Macintosh computer? No surprises here! Because of the limited supported for USB devices on such a new hardware system (even more so if using the early versions of OS X "Leopard"), you may have to wait for the manufacturers of the USB devices to provide software driver updates. Also migrating printer drivers from a PowerPC computer to Intel-based versions could be incompatible. Not even the migration utility provided by OS X can correctly migrate the software that is compatible, which makes the tool next to useless.

    On the USB front, you may have to look around for alternative USB devices that do work. Yes, you would be pleased to hear this recommendation. Welcome to Apple's new policy of getting you to constantly upgrade your system to make it compatible again.

    Or you may have better success adding a powered USB hub and connecting the USB devices to your computer. If OS X can recognise the USB hub, there is an excellent chance the other devices will be noticed!

    USB devices are recognised but misbehaving? This is almost certainly a driver problem. Update your driver now!

    Seriously, if all else fails, try the usual switching to a different USB port, unplugging and re-plugging the afflicted devices, and restarting your Mac (short of getting out a hammer and giving your Mac a good whack).

  • Printer problems have also come in for some criticism and problems, especially in the early versions of OS X. Most can be traced to a lack of or incompatible printer drivers.

    Looking for a printer driver? You are definitely in for some fun! We recommend opening the Printer Setup Utility (available to pre-Leopard users) located in Applications/Utilities, delete the printer device and re-add it. In fact, while you are at it, you might as well start from scatch by choosing the "Reset Printing System" option and clicking the Reset button. All devices in your Printer List will disappear. But at least you can add the devices one-by-one to refreshen the configuration files and force a permission check on the /tmp director. In fact, OS X "Leopard" users having trouble printing remotely to a printer connected to another Mac because of the error message "Unable to get printer status (forbidden)" may obtain relief using the above technique (if you have kept a copy of the Printer Setup Utility, which Apple has decided to remove for Leopard and Snow Leopard users). Otherwise, as one MacFixIt user has discovered for Leopard users:

    "I had the same problem. My wife's computer suddenly could not print anymore and got the "....(Forbidden)" error message. I traced the problem to CUPS not allowing remote users access to my printer, even though I've reinstalled the printer drivers, deleted and reestablished the printer on my computer, multiple reboots of all computers and printer.

    I looked at the /etc/cups files and noticed a significant size difference between older backup copies and more recent copies of the CUPS configuration file cupsd.conf.

    I fixed the problem by copying one of the old 23kb config files over the newer 1kb file using the CUPS web based editing function. [Point your browser to or http://localhost:631 and follow the instructions.]

    Both versions are very similar, except the old one had many comments explaining the statements, whereas the newer one had no comments at all. The one other significant difference between the config files is an entry that "requires user @SYSTEM" to remotely access the configuration file in the newer file. That might stop a remote printer daemon from accessing the printer and get you the "...(Forbidden)" error message.

    I also noticed that Apple in the 10.5.2 update changed many of the cups system files. lsbom lists new binaries for both /usr/sbin/cupsd and /usr/bin/cups-config, but not the config file itself." ( Remote printing problems in Mac OS X ("Unable to get printer status"); fix. 13 March 2008.)

    Or how about using your "Optional Installs" package on the Mac OS X installer DVD to find what you want (hopefully!)? The recommended procedure here is as follows:

    1. Drag the ~/Library/Printers folder into the trash can (do not empty).
    2. Restart your computer.
    3. Install the printer drivers you want from the "Optional Installs" OS X DVD disk.

    It doesn't matter if you think you already have the printer driver. It usually is a good idea to re-install the driver again using the above DVD technique as some users have had some success. As MacFixIt reader Michelle Steiner said:

    "I have an HP Photosmart 8450 printer connected via ethernet through a router. After transferring my previous G4 iMac's content to the Intel iMac, applications would crash when attempting to print anything. The only exceptions were applications such as Preview that had custom Print dialogs — but even they would crash if I clicked the "Custom" button to switch to the system print dialog.

    I reinstalled the printer driver (HP Photosmart 3.3) and it works fine." ( Special Report: Getting printers to work with Intel-based Macs. 30 March 2006.)

    This may extend to reinstalling the old PowerPC printer driver, which in some cases have fixed the printing problem.

    Can't find the printer driver on the Mac OS X Installer DVD? Goes to show how rough and ready your OS X and Intel Mac is from Apple (you need Snow Leopard 10.6.2 or higher to get away from this nonsense). Your next best shot is to visit the printer manufacturer's web site for updated Intel-native drivers. We call this the "cross your fingers and hope to hell there is something available" technique.

    Or have you tried printing a test page from CUPS? This is a long shot, but some users claim it might resolve some printing problems. Sounds more like trying anything just to get the bloody printer to work. But anyway, if it works, here is the technique:

    1. Open your web browser
    2. Type (or http://localhost:631) into the URL address field. Press Return. The CUPS administration page appears.
    3. Click on the "Manage Printers" link.
    4. Click "Print Test Page".

    Good luck!

    As for issues of not being able to find a printer on the network through AppleTalk automatically, try IP printing (you will have no choice but use IP printing after OS X version 10.6.2). This may necessitate walking around to the printer to figure out the IP address, but once you know it, type the address into AppleTalk. It is amazing how much a bit of leg work can go to resolve a printer problem.

    Did you consider the possibility of waiting 12 months or more to buy your "you beaut" Intel-based Mac so the printer manufacturers can have a chance to catch up? Never mind. It is nice to see you are trying to get ahead of the game now.

  • Having problems with DVI? Again, would you be using an Intel-based Mac? No surprises. The PowerPC version works okay. The Intel-based Mac seems hopeless in handling DVI as of June 2006. Try using a DVI to VGA adapter, or a DVI to S-Video adapter. Ignore the DVI to DVI cable adapter as this seems problematic.

    Alternatively, try to restart the computer while the digital projector is connected. Or try "Mirror Displays" in the Displays system preference pane (under the "Arrangement" tab).

  • When migrating software to the Intel-based Macs, remember that some application may misbehave (a classic example is Apple's iLife '06). Your options here are as follows:

    1. Delete preference (.plist) files relating to the troublesome application — that is, the one you can't seem to run properly on the new machine.
    2. Reinstall from the original disk the application on the new machine.
    3. Deinstall old versions of the application you think is misbehaving.
    4. Delete cache files created by the application which you have migrated to the new machine (they may contain incompatible information for the new environment). Most cache files can be found in ~/Library/Caches/.
    5. Wait until the software manufacturer comes out with a universal binary or Intel version of your application.

    The same is true of third-party plug-ins etc.


  • This is a powerful method of eliminating any form of corruption you may have acquired in OS X over time (short of programming errors on the part of Apple developers, which is why you need the right OS X update). Corruption problems have been known to cause a variety of issues including unexpected application behaviours, unable to modify permissions by the system, unable to access files and much more.

    For example, in this MacFixIt article of 4 September 2008, it is believed the best solution for users experiencing a situation where applying UNIX command line tools for managing user permissions and file accessibility using "sudo", "chown" and "chmod" may suddenly not work is to reinstall OS X. As MacFixIt stated:

    "When these administrative command line tools stop functioning, it indicates a major problem with either the core system or the filesystem."

    We recommend testing the disk for errors first and repairing any errors you find using Disk Utility and as a final resort try Disk Warrior. If the error cannot be fixed, reformat the disk and reinstall OS X.

    But before you do this, try to salvage as many files and applications as you can. Because once you reformat the disk, you will lose everything stored on the disk.

    And better still, always have a clean copy of a backup OS X on your disk (usually on a separate partition) so that you can switch the OS X and boot from a known clean and corrupt-free copy. Then you can see if there are differences in application behaviour and more.


  • Still having trouble? Well, did you know Apple is doing all it can to encourage people to regularly update and upgrade OS X and much of the third-party applications and file sharing tools through regular changes to OS X? For example, the Java updates issued after OS X version 10.3.6 has caused serious problems to Safari 1.3 when it comes to visiting Java-enabled web sites. Only by upgrading to Tiger 10.4.3 with Safari 2.0 (2) has most problems disappeared (although users will be deluged with a host of other problems to keep them busy). It may also be a ploy by Apple to force some people who aren't purchasing software (e.g. the pirates) to pay for their software (as discovered by the number of applications requiring some kind of an upgrade for compatibility with the latest OS X).

    NOTE: Apple also wants you to use the OS X DVD disk that came with your computer for maximum stability. Apple does not guarantee the retail version of OS X in a box has all the specific files you need for your specific computer especially the latest models. This, of course, means Apple can minimise software piracy of OS X and only a purchase of a Macintosh computer will guarantee all the files you need.

    NOTE: Apple again likes you to use the company's own Mail and Safari applications. No easy option to change to a different default application unless you have the original Mail and Safari applications (where you must go under the Preferences menu command). Try the freeware MisFox preference pane utility. It is a smaller and independent preference pane application designed to change the default settings for Web and Mail under OS X.

    If you are having problems with OS X, do not follow "the herd" so to speak and constantly upgrade/update. Stick to one good OS X version you know is stable and responsive. Based on the experiences of many OS X users, this should be OS X version 10.3.9 for "Panther" or version 10.4.9 for "Tiger". Trying to be an early adopter by updating to 10.5.x known as "Leopard" is only asking for trouble as users have found out (see this document).

    If you intend to update your OS X, make sure you use the full Combo updater (i.e. wait until Apple provides the lot in one file), and follow the spring-cleaning techniques above to minimise any inherent problems. In fact, you are probably better off waiting under the next OS upgrade and then choosing the most stable version of the older OS for installation (often at a bargain secondhand price). Then let the younger group of people with more money than sense to start complaining about the problems in the latest OS.

    This is the only way you can survive Apple's onslaught on the allegedly major software piracy problem.


  1. In the Accounts preference pane, set a password for your active user account. And, for goodness sake, don't tell anyone your password. Also make sure other people are not rudely looking over your shoulder when you type your password to access the account. If a Guest Account appears, disable or remove it. If you need to keep this account, consider removing all ticks in this account unless you want guests to access your computer or a shared folder from time-to-time. Should Guest access be necessary, it is safer to give guests access to a shared folder. So place a tick where it says "Allow guests to connect to shared folders". In the Sharing preference pane, you can specify the folder you want to share.
  2. In the Security preference pane, put a tick where it says "Disable automatic login" (you and anyone else having your computer must enter a password to get into your account); "Use secure virtual memory" (anything stored on the hard disk during sleep mode from RAM will be encrypted); and "Disable remote control infrared receiver" (some people may be able to control and access your computer with an independent infra-red tool).
  3. Turn on Firewall, press the Advanced button and put a tick where it says "Block all incoming connections".
  4. An optional security measure is to encrypt the Home Folder in the Users folder using FileVault. However take great care. OS X will create an encrypted disk image of the Home Folder. But should there be any file corruption to the disk image (especially common when you have low disk space), you could lose all your personal files. Only use if you have a large hard drive capacity and plenty of disk space and you definitely need the extra security (e.g. Defence or intelligence-related projects, commercially-confident information, or a book you are about to sell etc). Or manually create your own encrypted disk images using Disk Utility for storing only your most sensitive files. Use the highest encryption method possible (i.e. 256-bit).
  5. In the Sharing preference pane, remove the tick in all check boxes. Only put a tick in the correct box when you need to use a particular service to share something with someone on another computer or a separate device. Take care which Shared Folders you give others access to in the File Sharing section. And turn off Bluetooth Sharing unless you need others to share files with you via the Bluetooth method.
  6. Always turn off Bluetooth and Airport when not in use.
  7. Boot off your OS X installation DVD and set the firmware password. This means no one else can use another OS X installation DVD to reset your administrator account password (NOTE: Not foolproof as someone can remove the RAM cards and reinsert to reset the firmware password; but at least it makes it more difficult).
  8. Use the Parental Controls system preference pane to restrict web access to dubious web sites that could potentially compromise your security.
  9. Lock your keychain (contains your passwords for various applications, encrypted disk images etc) using Keychain in the Utility folder of the Applications folder.


  1. Backup all your data, applications, user folders and the System files to your external backup drive. In case you miss something after the transition to a new computer having a new hard drive or purchasing and installing a new hard drive, it would be a simple matter of rummaging through the backup disk for the file(s) you need. It makes for a smoother transition and the least amount of effort for you to get yourself back up and running as quickly as possible. Use a utility such as Carbon Copy Cloner to do all the backup work.
  2. You may be required to disable or deregister some online services or commercial software applications containing registration details that are based on some form of a hardware-based filtering (e.g. MAC address) to run their services or software. This may not be possible if your old hard disk has crashed unexpectedly and you cannot run the copy of OS X and/or the application or services that are on it. If necessary, you may have to contact the people running those services or have licensed the software to you to re-enable those ssrvices or software on your new hard disk and/or computer. Or move to other services or software that are not locked into the hardware of your computer to work.
  3. Reformat the hard drive. Use a single partition. And make sure you get the computer to properly insert zeros right throughout the disk. This is the longer method of erasing a drive but it is more secure. Otherwise people with file recovery tools can retrive your personal information, applications and other details. For the more security conscious, a 7-pass or 35-pass erase is the most secure but will take the longest time to complete. Potentially you could be waiting for days for a high capacity 300GB or more hard drive to be securely erased. You must decide on a suitable level of security or be happy to share your files with others. Or else purchase a second hand hard disk and install this into the old Mac.
  4. Use your OS X installation DVD to remove the firmware password and reset the SMC on the system. Also consider clearing the PRAM. NOTE: To reset SMC on a 17-inch MacBook Pro and MacBook Air, it may be as simple as plugging in the power cord for power, press Shift-Control-Option kets, and the power button once. Let the computer rest for a few seconds. Press the power button to start up the machine. For other machines, you may have to remove the battery for a few minutes.
  5. Reinstall a fresh copy of OS X. Always supply the original OS X installation disk that came with the computer.


  1. Press C during start-up: Start from a bootable CD/DVD, such as the Mac OS X Install disc.
  2. Press D during start-up: Start the Apple Hardware Test when the Install DVD 1 is inserted in your Mac's drive.
  3. Press and hold (Command + Option + P + R) until you hear two beeps: Reset the NVRAM.
  4. Press Option during start-up: Loads Startup Manager, enabling users to select which volume they would like to boot from. Pressing N will show the first bootable Network volume as well.
  5. Press the Eject button, press F12, or click and hold the mouse or trackpad button: Ejects any removable media.
  6. Press N during start-up: Attempt to start from a compatible network server (NetBoot).
  7. Press T during start-up: When two Macs are connected via FireWire, this will start one in FireWire Target Disk Mode (two Macs with FireWire ports are required).
  8. Press Shift during start-up: Starts your Mac in Safe Mode, temporarily disabling log-in items.
  9. Press (Command + V) during start-up: Starts in Verbose Mode.
  10. Press (Command + S) during start-up: Starts in Single-User Mode.
  11. Press (Option + N) during start-up: Start from NetBoot server using the default boot image.

Source: Aimonetti, Joe. Key combinations to troubleshoot your Intel-based Mac at start-up: CNET News. 25 February 2010.


  1. Using the Terminal utility, type diskutil erasevolume HFS+ "ramdisk" `hdiutil attach -nomount ram://128000`.
  2. Press the Return key. The Terminal will create a 64MB RAM disk called "ramdisk" on the desktop. You can change the name of the disk. And if you need to increase the RAM disk size, create a new RAM disk, but change the number in the terminal command from 128000 (64MB) to 256000 (128MB), 512000 (256MB), 1024000 (512MB) etc.

Ready-made Terminal script files to create RAM disks of each of these sizes can be downloaded here.

NOTE: Remember to keep a copy of the RAM disk contents on your hard disk before re-booting (and recommended before putting your computer to sleep).

Source: Aimonetti, Joe. Making RAM disks in OS X: CNET News. 19 October 2010.


Are you having one of those days when your Macintosh computer has decided to pack it in and go into an unassailable state of not booting up, screen is black, and the fans are run at high speeds and noisy? Welcome to the club of experienced Mac users who have been there and done that. All it takes is a bit of hair or dust (or did you touch certain crucial electronic components with your hand or some other material carrying a stray electric charge?) at a crucial part of the logic board (e.g. RAM area, video circuitry, etc) short-circuiting and causing damage.

You could take a long shot by trying all sorts of tests such as removing one or more RAM cards, disconnecting the hard disk and DVD player, clearing the PRAM, fully charging the battery, using the Option Command O F key combination and clearing hardware settings etc. But if all this fails, you can pretty much give the logic board the flick.

Before performing these tests, immediately shut down the computer by pressing the power button for about 5 seconds, disconnect power supply and battery and cross your fingers.

Given the price of some logic boards, you might be better off purchasing a secondhand computer of a slightly better manufactured model (e.g. microfine air flow grills rather than one where a cockroach could enter and make a home inside your computer; and consider giving away your cat or dog to someone who loves all the extra fur).