I upgraded from a 20gb to a 120gb hd. I saved my undo.bin from my 120gb wd harddrive. when i tried to restore it back to use it as a pc harddrive, it says wrong size. also i didnt' realize i have 2 files. one says Xboxbackup.bin (which is about 177mb- I don't know why it's so big), and another one is undo.bin 2kb. tried both, but same error.