Things You'll Need
Instructions
Back up any data on your USB drive to your computer. Formatting the drive for Xbox 360 use may wipe all existing data on the drive depending on your choices. Unless you have over 1 GB of free space on the drive after all existing files on it, you must dedicate the entire drive to the Xbox, so move files off accordingly.
Turn on your Xbox 360 and put the USB drive in one of the front USB ports. You will need to have updated your system since April 2010 in order to use the drive. This happens automatically if your console connects to the Internet. If not, connect it now and allow all updates to complete.
Scroll up or down to reach the "My Xbox" row of buttons, then scroll to the far right to "System Settings." Press "A" to select it.
Select the "Memory" option, and then look on the list for "USB Storage Device." Scroll down to this panel and press "A."
Decide whether you want your entire USB drive to be an Xbox memory unit, or if you want to split the space on the drive. To use the entire drive, select "Configure Now." This will wipe all data already on the drive and format it.
Select "Customize" if you want to split the space on the drive. A slider will appear allowing you to choose how much space to dedicate to the Xbox. 512 MB is the minimum amount you can choose, and the Xbox system will take up another 512 MB, so if your USB drive only has 1 GB, you must dedicate the entire drive.
Enter the Memory menu again after formatting finishes to see your USB drive now listed as a memory unit. You can now save game data to the drive.