Need help with my Xbox 360 120gb Hardrive. Wrong format !

[xxCoLLaTeRaLx]

Basically i got sent a used 120gb genuine xbox 360 Hardrive, I hooked it up to my xbox via transfer cable so i could transfer stuff from my 20gb hdd to the new 120gb hdd. When i turned on my xbox a screen was suppost to pop up asking if i want to transfer it accross. that did not happen so i went on the memory tab, It said i needed to configure the 120gb hdd to work on the xbox, After doing the it has not only made one partition in FAT32, and the xbox does not detect it anymore a Xbox HDD but just a USB device.

Can anyone please help me convert it back to FATx and fix this annoying problem.
My aim is: xxCoLLaTeRaLx

Any help would be majorly appreciated :]