A hacker named “TheSpecialist” has created a tool for your Xbox 360 that allows it to use any Hard Drive made by Western Digital (It has to be BEVS SATA. Lowest ones start at 40GB at $50 dollars). The tool makes the Hard Drive change file systems and because of it the file system will be 20GB no matter what drive you buy. Once this is made into a Xbox 360 File system, a computer will not be able to recognise it. However the creator states that it can be undone by running some special files.
It’s not a simple process and there are a lot of steps to it. If you are interested you should go check it out by going here.