How to Clear a Startup Disk on a Mac

By Jason Taetsch

Every type of computer is susceptible to virus infections and operating errors. If your Mac suddenly becomes unstable, use the disk utility to clear your startup disk to resolve any operating issues. The startup disk on your Mac is the volume that holds all the files and information for your Mac OS X operating system. Only clear the startup disk as the final step in the troubleshooting process because it will erase any of your personal files saved to the Mac's hard drive.

Things You'll Need

  • Mac OS X Install Disk

Step 1

Insert the Mac OS X install disc into your computer's disc drive. Double-click the "Mac OS X Installer" icon that appears on your desktop.

Step 2

Click "Utilities" in the window that appears and click "Restart." Wait for your Mac to restart and the Installer window to appear.

Step 3

Click your language in the "Language Chooser" menu, and click "Continue." Click the "Utilities" icon and click "Disk Utility." Click the "Startup Disk" in the list on the left side of the window and click the "Erase" tab.

Step 4

Click the "Format" menu and click the "Mac OS Extended" option. Click "Erase" to clear the startup disk on your Mac.