|Macintosh First Aid|
First Aid is a utility included with the Macintosh operating system for checking and repairing file system errors. In Mac OS X, it is part of the Disk Utility program. In earlier versions of the Mac operating system, it is a separate program called Disk First Aid.
It is a good idea to run First Aid or Disk First Aid once a month or so if you use your computer frequently to prevent major corruption to the files on your computer.
You should also use First Aid/Disk First Aid if your computer system is crashing frequently. It will check for defects and, in many cases, repair them.
To check your startup disk--the disk you start up your computer with (usually your hard disk), you have to run First Aid or Disk First Aid from the system or installation disk, CD or DVD that came with your computer.
If you are inserting a CD or DVD, while you restart your computer press and hold down the c key on your keyboard to force your computer to start up from the CD/DVD. Then open First Aid or Disk First Aid (see steps for OS X and earlier operating systems below).
Use First Aid in OS X
Use Disk First Aid in OS 9 and earlier
Caution: You should run only the Disk First Aid that came with your Mac OS 8.1 or later or download the latest Disk First Aid directly from Apple.com. Running an older version of Disk First Aid could corrupt your files.
First Aid or Disk First Aid results
The results of a verification and/or repair are displayed in the First Aid window. You should run First Aid repeatedly until you see the following message at the end of the scan: "The volume [your disk name] appears to be OK."
Sometimes, at the end of a scan, a message appears that says: "Scan complete. Problems were found, but Disk First Aid cannot repair them." In that case you can either check your back up copies of the affected files to see if they are okay and you can then replace the corrupted ones or you can try a commercial file repair or recovery program.