Erase and reinstall OS X Mavericks

Erase your Mac, then reinstall OS X using the built-in recovery disk. Before you erase, back up your essential files. If you’re installing on a portable computer, make sure your power adapter is plugged in.

Important: To reinstall OS X, you must be connected to the Internet.

  • Choose Apple menu > Restart. Once your Mac restarts (and the gray screen appears), hold down the Command (⌘) and R keys.
  • If you’re not connected to the Internet, choose a network from the Wi-Fi menu (in the top-right corner of the screen).
  • Select Disk Utility, then click Continue.
  • Select your startup disk on the left, then click the Erase tab.
  • Choose Mac OS Extended (Journaled) from the Format menu, enter a name, then click Erase.
  • After the disk is erased, choose Disk Utility > Quit Disk Utility.
  • Select Reinstall OS X, click Continue, then follow the onscreen instructions.