OR
in order for your Xbox360 to detect your hard drive needs to be formatted the correct way and have
Windows FAT32 file system format. or it will not even detect it on both external and internal hard drives. In short you may
need a special, free, or costly program. in order to convert the hard drive into FAT32 Format if you have Windows 10 on your PC/computer but if your computer has windows 7 or sooner like XP you shouldn't need a special program
there is a command prompt hack for formatting FAT32 in windows 10 but I forgot how sorry
if you got windows 7 or sooner than, plug in your hard drive into your PC than, right click on the external hard drive, than click format . Please note this option is not available in windows 10