Things You'll Need
Instructions
Connect the external USB hard drive to a USB port on your computer.
Click on the "Start" button on the bottom-left corner of your desktop to open the Start Menu. Click on "Computer."
Right-click the external USB hard drive and choose "Format..." from the menu that appears.
In the Format menu, click the drop down button under "File System" and choose "FAT32." Then click the "Start" button at the bottom of the window.
Disconnect the hard drive from your computer by right-clicking the external USB hard drive and choosing "Eject" from the options.
Plug the external USB hard drive into one of the USB ports on the Xbox 360 and turn on the console.
Scroll to the "System" tab on the Xbox 360 Dashboard and select "Memory." Choose the external USB drive instead of the regular Xbox 360 hard drive to access the newly formatted drive.