OS X Lion: About Lion Recovery
About Lion Recovery
Recovery HD
OS X Lion includes a built in set of utilities in the Recovery HD. Restart your Mac and hold down the Command key and the R key (Command-R), and keep holding them until the Apple icon appears, indicating that your Mac is starting up. After the Recovery HD is finished starting up, you should see a desktop with a Mac OS X menu bar and a "Mac OS X Utilities" application window. Note: If you see a login window or your own desktop and icons, it is possible that you didn't hold Command-R early enough. Restart and try again.
In order to reinstall OS X Lion, you will need to be connected to an Ethernet or Wi-Fi network. The Wi-Fi menu item is in the upper-right corner of the screen. Click the icon to display all available Wi-Fi networks. Click your preferred network name and, if needed, enter a username and/or password.