How to Do a System Restore on an iMac

By Teresa Starr

If your iMac has been infected by a virus, is running slowly, or having other system issues, a system restore will restore your iMac to the factory settings, removing any system problems. No matter if you are a beginner or advanced iMac user, completing a system restore is a task that anyone can do by using the Mac OS or Mac OS X installation CD. Always remember to save any important documents, folders, or media files to a CD or DVD before completing a system restore.

Things You'll Need

  • Mac OS or
  • OS X installation CD

Erase the Hard Drive

Step 1

Turn on your iMac.

Step 2

Insert the Mac OS or Mac OS X installation CD into the CD/DVD-ROM drive of your iMac.

Step 3

Press the "C" button as your iMac begins to boot up, ensuring that your computer will boot from the installation CD.

Step 4

Click on the "Utilities" menu when a new window pops up, and then click on "Disk Utility."

Step 5

Select "Macintosh HD" and then click on the "Erase" tab. A dialoge box will pop up. Once this happens click "Erase". This will erase your hard drive.

Step 6

Click on "Quit Disk Utility" once the partition is erased.

Install the Operating System

Step 1

Click "Continue" when the next window pops up after you have closed "Disk Utility". This will open up the OS or OS X Leopard Installer screen.

Step 2

Click "Agree" when the license agreement pops up.

Step 3

Click the green highlighted arrow in the window that pops up. This highlighted arrow is pointing to the disk you just erased.

Step 4

Click "Install". Mac OS or OS X will now begin to reinstall. There will be status bar at the bottom of the screen, indicating the progress of the installation.

Step 5

Click "Continue" once the installation has completed. Click "Restart" once the "Installation Successful" screen pops up. You have now performed a system restore on your iMac.