Instructions
Plug your hard drive into your Xbox 360, if necessary, then turn on the console.
Open the "Home" menu by pressing the "Guide" button on the controller.
Choose the "Settings" blade from the resulting pop-up menu.
Choose "System Settings" from the "Settings" blade. The menu will close and a new "System Settings" screen will appear.
Select "Memory." A new screen will appear where you must select a storage device.
Scroll to your "Hard Drive," then press "Y." A hard drive "Options" page will appear.
Choose "Clear System Cache" from the "Options" screen. A prompt will appear informing you that choosing this will perform maintenance on the hard drive.
Select "Yes" to begin performing maintenance on your hard drive.