Remove Your Xbox 360 Drive
Microsoft expects you to pay close to $200 to upgrade your Xbox 360's hard drive from 20GB to 120GB. That's about $150 more than a 120GB SATA drive actually costs. But with this slightly tricky hack, you can save a bundle while boosting your game console's storage capacity to hold more music, video, and other media files.
You'll need a DOS installation on a writable flash thumb drive for this hack. (The utility doesn't work under Windows, and you'll also be disconnecting your PC's hard drive.) First, grab a spare USB thumb drive and copy the HP Drive Key Boot Utility to it. The utility is designed for HP flash drives, but it works on other types of flash drives, too. Also download and mount a DOS image file.
This hack is designed to work with a specific drive, the 120GB Western Digital Scorpio, model number WDGWD1200BEVS. You'll be replacing the drive's native firmware with Xbox-recognized firmware. You can track down the firmware online by doing a search for "hddss.bin 120 Xbox 360." Place the hddss.bin file in the root of your DOS thumb drive.
Once you have these items and files ready, begin the upgrade by removing your Xbox 360's hard drive from the game console.
(For more hands-on hacks, see "Extend Your Wi-Fi Range With a Parabolic Reflector," "Add a Second Hard Drive to Your TiVo," and "5 Laptop Upgrades You Can Do Yourself.")
Open the Drive Enclosure
Use a Torx screwdriver to open the drive enclosure, exposing the interior drive cage. Next, remove the four screws holding the drive into the cage.
Slide Out the Drive
With the retaining screws removed, disconnect the drive from the SATA-and-power cable, and slide the drive out of the enclosure.
Install the New Drive in Your PC
With your PC turned off, unplug any other SATA devices and then connect the new Scorpio drive to one of the SATA cables and to a power lead.
Boot From the Thumb Drive and Format the Hard Drive
Afterward, boot from your DOS thumb drive (specify a boot drive in your PC's BIOS, if necessary). At the DOS command line, type "run hddhackr –f" (don't include the quotation marks) and press Enter. You'll be prompted to make a backup of the original drive firmware; do so. Continue with the process to flash the firmware on the new hard drive. After a few seconds, you'll be prompted to restart the computer. Once you have done so, run the "hddhackr –f" command again, and it should report that the hard drive has been formatted for the Xbox 360.
Install the New Drive in the Xbox 360
Remove the newly formatted 120GB drive from your PC and install it into the Xbox 360 drive enclosure. Put the enclosure back together, reattach it to the console, and turn the console on. Follow the prompt under 'System, Memory' to format the new drive; after formatting is complete, the drive will be ready for use.