Repairing, Restoring, or Reinstalling Mac OS X Software
If you have a problem with your Mac software or hardware, Mac OS X provides repair and restore utilities that may eliminate problems and can even restore your software to its original factory settings. You can access these utilities from the Mac OS X Utilities application, even if your computer isn’t starting up correctly.
Use the Mac OS X Utilities application to:
ÂÂ Restore your software and data from a Time Machine backup. ÂÂ Reinstall Mac OS X Lion and Apple applications.
ÂÂ Repair your computer’s disk using Disk Utility.
