Mac OS X First Aid

Welcome to square one. When you're troubleshooting in Mac OS X, most of what you learned about OS 9 is irrelevant. There's no more rebuilding the desktop, no more isolating extension conflicts--OS X is much more than an upgrade to Mac OS; it's an entirely new operating system. When trouble strikes (and it will), your reliable set of OS 9 remedies will be of little help.

Now that Apple is including OS X on every system it sells, and with a major update of OS X on its way, you need to know how to keep your new operating system in excellent condition--and that's where this article comes in. It provides a first-aid kit for nursing OS X back to health when problems arise. For everything from system crashes to files that won't go into the Trash, here's what you need to keep your Mac OS X system in good health.


Applications can freeze in Mac OS X, just as they do in OS 9--most commonly resulting in an endlessly spinning beach-ball cursor. However, unlike in OS 9, freezes in OS X don't usually bring your Mac to a screeching halt. If you click on a window belonging to an application other than the frozen one, the Mac responds normally. Still, you'll probably want to thaw out the frosty application, especially if you need to use it again. Here are the steps to take:

1. Use Force Quit If you've used command-option-escape to force quit an application in Mac OS 9, you'll be pleased that this keyboard command works in OS X. Alternatively, you can select Force Quit from the Apple menu. Either method brings up the Force Quit Applications window (see "Force Quit"). From here, you get to select which application (including the Finder) you want to quit.

2. Use Process Viewer In Mac OS X, some programs (the Dock, for example) run behind the scenes. Since you didn't launch them, they aren't listed in the Force Quit Applications window. Still, you may someday need to quit one. A Dock icon may stop working, for example, or the "puff of smoke" that appears when you drag an icon off the Dock may not disappear as it should. If this happens to you, quitting and then relaunching the Dock may be the cure. This is where Process Viewer (found in OS X's Utilities folder) comes to the rescue. Launch it, and select the Dock process from the list that appears (see "Dock Quit"). Then select Quit Process from the Processes menu. The Dock will vanish and then reappear in about ten seconds.

Force Quit To get out of a freeze, the Force Quit Applications window lets you choose an application to force quit.

Dock Quit To quit processes not listed in the Force Quit Applications window, use Process Viewer.

3. Log Out or Restart If neither Force Quit nor Quit Process works, select Log Out from the Apple menu to log out, and then log back in. This almost always fixes a freeze. (And because the freeze probably affected only one application, you can save your work in any other open applications before doing this.)

With those rare freezes so severe that you can't get the Log Out command to work, you may need to restart your Mac. However, before you do, let it sit idle for a minute or two. This gives it a chance to write cached data from RAM to the hard disk (something it may still be able to do, despite the freeze), possibly preventing data corruption. After you've done that, use whatever method works with your particular model (pressing command-control with the power button on laptops or with the reset button on desktop Macs).


Most Mac users have come across the dreaded system bomb from time to time, but the types of crashes that cause it do not occur in Mac OS X. Don't start celebrating quite yet, though--OS X has its own version of the system crash. It's called a kernel panic-- and it's just as debilitating as any OS 9 crash. A kernel panic happens when the underlying Unix core that Mac OS X depends on fails. You'll know it's happened to you if strings of text containing error messages appear over the current display on your screen--right before everything stops working.

Kernel panics are rare but can be triggered by familiar demons: corrupted software, a software bug, or incompatible hardware. For example, as of OS X 10.0.4, a kernel panic may occur if you eject a CD while the iTunes application is opening; if you start up with a blank CD in a SCSI-connected CD-RW drive; or if third-party RAM isn't within your Mac's specifications, even if that RAM works fine in OS 9. Here is how to recover from a kernel panic:

1. Restart If a kernel panic occurs, just restart your Mac--you should be fine.

2. Reinstall or Check for Updates Typically, the only thing you can do to prevent the panic's return is to avoid whatever caused it. In the long term, you need to get a bug-fix upgrade to the offending software. An update may already exist; to find out, run OS X's Software Update and check sites such as Otherwise, on the off chance that the kernel panic was caused by corrupted software rather than a bug, try to reinstall the suspected culprit.


When your Mac won't even start up, you know you're in trouble. In Mac OS X, that problem can take any of several forms. You may wind up with a blank "blue screen of death" or a ripped-in-half System Folder icon, or--most unsettling for a Mac user--you may get dumped into a command-line mode displaying several lines of error messages. Try the following tricks:

1. Reboot in OS 9 On most OS X-supported Macs, you can hold down the option key while restarting to bring up a window where you can select which OS you want to use. Select the OS 9 start-up icon. In OS 9, open the Startup Disk control panel. Make sure you're using version 9.2.1 or later of Startup Disk (run Apple's Software Update control panel to see whether you have the latest version), as earlier versions may cause problems when you try to switch to OS X. Then select an OS X system and restart. With luck, OS X will now start up.

First Aid Disk First Aid, Apple's well-known OS 9 repair utility, survives as part of Disk Utility in OS X.

2. Disconnect Hardware Certain SCSI cards and USB hubs are among several hardware peripherals linked to start-up crashes. The workaround? Remove the card or device from your Mac. Then check with the hardware manufacturer (or a Mac Web site, such as my own MacFixIt ) for information about a possible permanent solution (such as an OS or firmware update that allows the card or device to work). In some cases, you can still use the hardware if you reconnect it after start-up.

3. Run a Disk-Repair Utility You may be able to fix your start-up problem by repairing corrupted data. Disk First Aid, part of the Disk Utility application that comes with OS X, is designed to do just that (see "First Aid"). Unfortunately, the current version of Disk First Aid won't make repairs to the start-up volume. The solution is to restart from the OS X installation CD, select Open Disk Utility from the Installer menu, and use Disk First Aid to attempt to repair your drive.

As of this writing, there's only one third-party repair utility that can run from Mac OS X: Micromat's $70 Drive 10 (800/829-6227, ). However, the latest versions of Alsoft's $70 DiskWarrior (800/257-6381, ), Micromat's $98 TechTool Pro, and Symantec's $100 Norton Utilities (800/441-7234, ) can all make repairs to OS X volumes when run from OS 9. They may be able to fix problems that Disk First Aid misses.

4. Run fsck If you don't have a Mac OS X installation CD or another repair utility handy, all is not lost. Restart, and hold down command-S. This dumps you into single-user mode. You'll see a distressingly long block of white and yellow text against a black background. Don't despair; this is just a variant of OS X's Unix command-line interface.

When the scrolling has stopped and you can actually enter text, type /sbin/fsck -y and press return. This will initiate a Unix repair function called fsck (for file system check ). In OS X, Apple has added Disk First Aid code to this function. If fsck makes any repairs, you'll get a message that says "File system was modified." Run fsck again until the message no longer appears. (The first run may uncover additional errors that will require a further run to fix.) Once all repairs are made, type reboot and press return.

If you get the start-up error that dumps you immediately into the command-line interface, you can run fsck directly from there, without needing to restart.

5. Reinstall OS X Corrupted files in the OS X Library folders can cause a start-up crash. Though you can spend time trying to track down and remove the offending file(s), it's often easier to start up from the OS X installation CD and reinstall OS X (being careful not to select the option that erases the disk). Doing this will leave almost all your custom changes intact. But if you've updated the OS to a version that's newer than the one on the CD, you'll have to reinstall those updates, too. If an initial reinstall doesn't work, try restarting from OS 9 and deleting the entire OS X System Folder. Then restart from the OS X installation CD and reinstall the operating system.


OS X will sometimes refuse to let you move a file to the trash--typically informing you that you don't have "sufficient privileges." You may get the same sort of error message when you try to copy, move, or open a file. Unlike OS 9, OS X requires you to log in with an identity every time you start up. Depending on the privileges associated with your log-in, you may run into problems (see "How Privileged Are You?" for more information). Here's how to get OS X to cooperate:

1. Unlock the File A common reason for the inability to delete a file in OS X is that the file is locked. The easiest way to fix this--if it works--is to deselect the Locked option in the file's Show Info window (similar to OS 9's Get Info windows). You may run into trouble if the file was locked under OS 9. In that case, try DropNuke ( ). This freeware utility should unlock and delete any file or directory of files dragged onto it. Otherwise, go back to OS 9 to unlock and delete the file.

Occasionally, OS X may allow you to place a file in the Trash but then refuse to delete it. If that happens, try placing the file in a folder and dragging the folder to the Trash before selecting Empty Trash. You can also try to reboot in OS 9 and delete it. Be careful to remove the file from the Trash before switching to OS 9, or you may have trouble locating it.

2. Run Disk First Aid If the file isn't locked, start up from the Mac OS X installation CD and run Disk First Aid as described earlier. There may be a problem preventing you from deleting the file; hopefully, the utility will fix it.

3. Be an Administrator Still no luck? Open Users System Preference. For the name of the currently logged-in user, look in the Name column. Then check the Kind column (see "Three of a Kind"). If the Admin designation does not appear next to your name, you're not an administrator. There are some things an administrator can do that other users can't. For example, regular users can't add files to or remove them from the Applications folder.

If you're an administrator and another user isn't (for example, if your daughter has her own log-in on the home computer), you can opt to give that user administrator status as well. To do this, highlight the user name and click on Edit User. Select the Allow User To Adminis- ter This Machine option, and then click on OK.

4. Get Root Access (If Needed) Mac OS X occasionally blocks you from modifying certain files even if you're an administrator. Prime examples are the files in the System Folder. If you try, for example, to move a file from the System Folder, you'll get a message such as "The operation cannot be completed because you do not have sufficient privileges for item or folder name " or "The item item name could not be moved because system cannot be modified." The rationale behind this is to protect these essential files from accidental harm--not a bad idea, because you usually have no need to mess with these files. However, if you are an administrator and you want to modify the contents of the System Folder, you can do so by giving yourself root access. There are several ways to accomplish this bit of OS X magic.

Three of a Kind To make a user an administrator, select his name, click on Edit User, and choose the appropriate option.

Root of the Matter To enable root access (or disable it, if it's already been enabled), use NetInfo Manager.

One method is to log in as the root user. Before you can do that, you have to set up a root account. Select OS X's NetInfo Manager (see "Root of the Matter") via its Enable Root User command (after first clicking on the lock icon to allow changes to be made, choose Domain: Security). You can also start up from the Mac OS X installation CD and select the Reset Password command from the Installer menu. From there, select System Administrator (Root) from the pop-up menu that appears and establish a password. Once you've set up the account, restart as usual and enter the word root as your user name, along with the password you selected. You will then have access to nearly everything on the drive. Be aware that logging in as root can be dangerous: the root can bring down a system by mistakenly deleting or modifying the wrong files.

Another method involves the $15 shareware application Pseudo ( ), which essentially grants you root access in a limited way, circumventing the need to log in as root. It lets you launch an application that you couldn't otherwise launch (or open documents that you couldn't otherwise open) unless you had root access or went to the command line. To use it, simply drag onto the Pseudo icon any application you want to work with. The program will open, prompting you for your admin password along the way. After entering the password, you'll have root access to the application and to any files you open from within it. This means that you can use TextEdit to open documents (such as preferences files) in the System Folder or even in OS X's invisible Unix directories; you would otherwise be prohibited from opening them.


How often do you get an e-mail attachment--a picture from your parents' trip to the Grand Canyon, say--and find that double-clicking on it sends your Mac into a confused search for an application that can display it? When you double-click on a document icon in Mac OS X, the file should automatically open in an appropriate application--typically the one that created it. But OS X may sometimes open the wrong application or even claim that no application is available to open the document. Here's how to avoid that problem:

1. Check for Updated Applications The version of Microsoft Internet Explorer that came with the initial release of Mac OS X has a problem decompressing files: it tries to launch a version of Expander from OS X's Classic mode rather than one available in OS X. Update to the latest version of Explorer to fix this.

2. Check for Fix-It Utilities In some cases, .dmg (disk image) files downloaded from the Web show up in Mac OS X as text files. Double-click on them, and you launch TextEdit rather than Disk Copy. You can work around this by dragging the image file's icon to the Disk Copy icon or by mounting the image from within Disk Copy. If you find these extra steps annoying, you can use "a freeware utility called DMG Fixer ( ). Just drag the problem file's icon to the DMG Fixer icon, and the utility will permanently fix the file. Afterward, you'll be able to open the file correctly by double-clicking on it.

3. Place the Application in the Dock If you've got two versions of the same application on your drive (for example, one for OS 9 and another for OS X), and documents for that application open by default to the wrong one, drag the preferred application's icon to the Dock. Typically, OS X will open that version of the program by default when you double-click on documents created with it.

4. Make the Application Open the File From the Application pane of the problematic file's Show Info window (see "Quick Change"), select Open This Document With A Specific Application. To change the listed application, click on the application's icon, and from the pop-up menu that appears, select Add Application. In the resulting window, select the desired application. If the application you want is dimmed, change the Show pop-up menu from Recommended Applications to All Applications. Remember, however, that this will fix the problem only for that particular file.

5. Get More Document Control To get all files of the same type to open with an assigned application, select Show Info: Open This Document With The Generic Applica-tion For Documents Of This Type, and if necessary, click on the Change Application button to select the application you desire.

If the Change Application button is dimmed or otherwise doesn't work, try the xFiles shareware utility ($20; ). It won't always fix the problem, but it's worth a try. Launch the utility, and drag the file that you want to modify to the xFiles window. Delete whatever code is listed in the text box next to Creator. Click on Change. Now double-click on the file. It may already open in the correct application. For example, I had a document that launched PictureViewer in OS X's Classic environment when I double-clicked on it. After I eliminated the Creator code, it opened in OS X's Preview. If that doesn't fix it, return to the Show Info window; the Change Application button should now be enabled. Select the desired application.

6. Change the File-Name Extension Unlike Mac OS 9, Mac OS X uses file-name extensions (suffixes that are appended after a period to a file's name, such as .doc for Word documents) to identify the document type. For example, files with a .txt extension will open in TextEdit by default, while graphics with a .tif extension will open in Preview. Assuming you know what extension you want, simply append it to change a document's icon as well as the application that opens it. For example, change a text document's extension from .txt to .cwk and it will open in AppleWorks instead of in TextEdit. You may still need to eliminate the Creator code, as described in the previous tip, before this will work.


Mac OS X, like any new OS, will have to contend with a few aches and pains as it matures. Fortunately, this operating system has a lot of people working to keep it healthy. From tips on how to best use the features built in to OS X, to freeware and shareware utilities that provide the features Apple omitted, troubleshooters have already given us a well-stocked medicine cabinet filled with remedies.

Contributing Editor TED LANDAU is the editor of MacFixIt, where you can find new information about troubleshooting Mac OS X every weekday.

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