Treat panic attacks
It’s an ominous sign: your screen just turned a shade darker and displayed a message—in several languages—informing you that you must restart your computer. Your Mac is suffering from a kernel panic. But despite the name, there’s no need for you to panic if you experience one.
1. Restart The first step is to just restart your Mac, as the dialog box requests. Near the end of the startup, a “this application has unexpectedly quit” message will appear. Don’t worry: your Mac is merely informing you that OS X itself quit unexpectedly before your restart.
2. Check for Updates Like application crashes, kernel-panic problems often vanish after a restart. If not—and if the onset of the panic is linked to a specific application—there’s almost certainly a fatal bug in that software. Contact the maker for an updated version or for advice.
3. Ax New Hardware Have you recently added RAM or a PCI card to your Mac? Regard such hardware additions with suspicion, especially those that add a kernel extension with the word Driver in its name to your computer’s /System/ Library/Extensions folder. These extensions can be potential sources of kernel panics. If you recently added something to your Mac, see whether removing it eliminates the panic. (For more about RAM problems, see Is Your Memory Bad? )
4. Try a Safe Boot If the kernel panic occurs at apparently random moments, or during startup, try a Safe Boot. Restart and immediately press the shift key, holding it down until a blue screen appears. The Safe Boot initiates a series of OS X repairs.
5. Reinstall OS X If the Safe Boot succeeds but a kernel panic strikes again when you boot normally, a file in the /System/Library/Extensions folder is usually the cause of the panic. The file was probably installed by a third-party application, and the simplest solution is to reinstall OS X and then reinstall your third-party software only as needed until you find the program that triggers the panic.
[ Contributing Editor Ted Landau continues to search for new ways to get into and out of trouble. For more troubleshooting tips, see his book Ted Landau’s Mac OS X Help Line: Tiger Edition (Peachpit Press, 2006). ]