Changing a hard drive from FAT32 to FATX will allow you to use it in an Xbox 360. FATX is a modified version of the FAT32 file system that is specific to the Xbox 360 platform. Sometimes a hard drive needs to be replaced. If the hard drive is replaced with a nonfactory drive, then it will need to be formatted to FATX before the Xbox 360 can use it.
Look at the back of the Xbox 360. Find the serial number and write it down. Open the Xbox 360 enclosure. Insert the replacement hard drive. Connect the SATA and power cable to the enclosure. Close the enclosure.
Replace the enclosure onto the Xbox 360. Power on the console.
Press the Xbox button in the centre of the controller. Scroll to the "Settings" pane. Select the "System Settings" option. Press "A."
Select the "Memory" option and press "A." Select the hard drive and press "Y." Select the "Format" option and press "A." Enter the serial number. Press "A." This will format the new drive to FATX and make it usable.
You can also format a USB stick to FATX using the Xbox 360.
Replacing your hard drive with a non-OEM part may void your warranty.