If you reinstall Lion / Mountain Lion on a new Mac that shipped with OS X Lion / Mountain Lion installed, on an erased or replaced hard drive, you can download iPhoto, iMovie, and GarageBand from the Mac App Store.
- After installation, start from Lion / Mountain Lion
- Double-click the App Store icon in the dock.
- Enter your Apple ID and password.
- Click Purchases.
- If you haven't previously accepted your bundled iLife applications within the Mac App Store, you should see your iLife applications appear in the Accept portion of the screen. Click Accept.
- You may be asked for your Apple ID and password once again. Your iLife applications now move to the Purchased section. These applications are part of the software that came with your Lion based computer. Your account will not be charged for them. Click Install to compete installation of your applications.