OS X Mountain Lion: Recover your entire system
If you use Time Machine to back up your computer, you can recover your system’s contents if your system or startup disk is damaged.
If you’re restoring your system because of a problem with your startup disk, repair or replace the disk before following these instructions.
- Make sure your Time Machine backup disk is connected and turned on. If your backup disk is on a network, make sure your computer is on the same network.
- Choose Apple menu > Restart. Once your Mac restarts (and the gray screen appears), hold down the Command (⌘) and R keys.
- Select “Restore from a Time Machine Backup,” and then click Continue.
- Depending on your type of backup disk, do one of the following:
If you use an external disk, select it and click Continue.
If you use a Time Capsule, choose your AirPort network from the AirPort menu on the right side of the menu bar, and then select your Time Capsule and click “Connect to Remote Disk.”
If you use a network disk, select it and click “Connect to Remote Disk.”
- If necessary, enter the name and password you use to connect to your backup disk, and then click Connect.
- Select the date and time of the backup you want to restore, and then follow the onscreen instructions.
After you restore your system from a Time Machine backup, Time Machine may perform a full backup at the next scheduled backup time. This is normal. Time Machine resumes incremental backups after the full backup is completed.