Original 20g 360 Drive Problem, console won't recognise it Options

[Treadstone]

Hi bought a used 20g drive off ebay as faulty,whoever had it had done something so it wouldn't show up when in the 360, I've used 360 explorer to copy my hd onto this one but still won't show up in the console.when i connect it to my pc it says it needs to be formated before i can use it,which it doesn't when i put my original in.so i think its format is knacked up,Is there any way i can format it to fatx so the 360 can see it.In 360 explorer all 3 partitions are there with the folders in,just the 360 won't recognise it.thanx in advance