Problem: My computer freezes or crashes during the startup process (before you see the desktop).

Solution:

Don't Panic. Crashes during startup are usually caused by one of a few possible problems:

• An extension conflict: Try holding down the SHIFT key as your computer starts up. If it no longer freezes, that probably means that you have an extension conflict.
  

• Problems with the "PRAM": If your computer still freezes while holding down the shift key, there might well be a problem with the PRAM. Resetting, or zapping, PRAM may solve the problem.
  

• Problems with the Hard Drive: There may be problems with the hard drive, especially if you've been crashing a lot lately.
  

• Operating System: It may be that you will need to reinstall the Mac OS. If all of the above options have failed, your system may need to be reinstalled. Detailed information on Mac OS Support at Cornell is available here.
  

• Hardware problems: If the RAM, ROM, expansion cards or other hardware are damaged or not connected properly, that can cause problems. These sorts of problems often cause a "Sad Mac" when you turn on the computer. Hardware problems of this sort are best solved by a trained repairman, which can be found in the Yellow pages - make sure to look for an Apple-authorized service provider. If all of the previous options have failed the problem may be due to a hardware conflict.