Instructions
Turn on the Xbox 360 console to open the Dashboard menu.
Highlight “My Xbox” in the Dashboard menu.
Select “System Settings” from the “My Xbox” section of the menu. Press right on the controller to scroll through the “My Xbox” section options. Press the “X” button on the controller to select it from the menu.
Select “Memory” from the system settings. It is the third option from the top of the list.
Highlight the Xbox 360 hard drive in the storage devices selection menu.
Press the “Y” button on the controller to open the hard drive options menu. “Clear System Cache” may not initially be visible on the menu. This is the option needed to defrag an Xbox 360 hard drive.
Press “X,” “X,” “Left Bumper,” “Right Bumper,” “X,” and “X” to add “Clear System Cache” to the menu. This is not necessary if this option is already visible.
Select “Yes” on the confirmation prompt. A status bar will appear. The system cache will be cleared and the hard drive defragged when the process is complete.