Things You'll Need
Instructions
Disconnect all power cables and accessories from the Xbox 360, but leave the hard drive attached. Remove the front faceplate then unclasp the tabs on the outer case and remove it. Unscrew the Torx screws on the interior metal case and slide it open. Unplug the SATA cable from the DVD drive to the Xbox motherboard, then connect your SATA cable from your computer to the Xbox motherboard. Turn on the computer.
Open a Web browser and download an Xbox modification program from the list in the References section. Run the program, then select your Xbox from the main menu. Click "Hard Drive Options," then click "Partition Hard Drive." Click "OK" and the program will begin partitioning your Xbox 360 hard drive so it can be used to run custom code and games.
Close the program and turn off the computer once the partition process is complete. Disconnect the SATA cable from the computer to the Xbox motherboard, then reconnect the SATA cable from the Xbox motherboard to the DVD drive. Close the metal interior case then rescrew the Torx screws. Replace the outer case and front faceplate. Reconnect all power cables and accessories