Apple iMac (21.5-inch and 27-inch, Mid 2011) - Manual (Page 53)

53 Chapter 4 Problem, Meet Solution
Restoring Information Using a Time Machine Backup
You can use the Restore utility to restore everything on your computer to its previous
state if you have a Time Machine backup.
Use your Time Machine backup to restore information only to the computer that was
the source of the backup. If you want to transfer information to a new computer, use
Migration Assistant (in the Utilities folder in Launchpad).
1 If your backup is on a Time Capsule, make sure you’re connected to an Ethernet or
Wi-Fi network. (To connect to a Wi-Fi network, follow the instructions on page 52.)
2 In the Mac OS X Utilities pane, select Restore From Time Machine Backup and
click Continue.
3 Select the disk that contains the Time Machine backup, and then follow the
onscreen instructions.
Reinstalling Mac OS X and Apple Applications
Under some circumstances, you may need to reinstall Mac OS X and Apple applications.
You can reinstall while keeping your files and user settings intact.
1 Make sure you’re connected to the Internet by using an Ethernet or Wi-Fi network.
(To connect to a Wi-Fi network, follow the instructions on page 52.)
2 In the Mac OS X Utilities pane, select Reinstall Mac OS X and click Continue.
3 In the pane where you’re asked to select a disk, select your current Mac OS X disk
(in most cases, it is the only one available).
4 To select or deselect optional software, click Customize.
5 Click Install.