How to enable the OS X 10.5 (Leopard) Time Machine feature to create backups of your system state.

1. Open System Preferences under the Finder menu. Then Time Machine.

2. Open Time Machine preferences.

3. Set the switch to ON.

4. Click Change Disk.

5. Select the disc you want Time Machine to utilize for backups and click Use for Backup.

Now at anytime you can revert back to a previous system state. It’s very useful for when you accidentally delete something and would like to get it back.