Time Machine

Format the External Hard Drive

1. Open Disk Utility (Applications-->Utilities-->Disk Utility)
2. Insert the external hard drive into your USB port.
3. On the left-hand side pane of Disk Utility, your external hard drive should appear.
4. Click on the External Hard Drive (below the computer's drive) once to select it.
5. On the right-hand side, find the the Erase menu, click it once.
6. Choose MacOS Extended (Journaled).
7. Rename the external hard drive to BACKUP DRIVE.
8. Click the Erase button.
9. Click Erase

Use Time Machine

1. Open System Preferences
2. Click Time Machine
3. Click Select Backup Disk
4. Choose the External Drive you named BACKUP DRIVE
5. Click Show Time Machine in menu bard (bottom of the Time Machine System Preference Pane)

Run Backup

1. In the menu bar (in the top right hand corner), click the Time Machine icon, and click Start Backup Now