Howdy. While I use Macs, I got this windows 7 laptop that I have hooked up to my TV and basically use as a media center. Its internal HD is 320gb's. I never backed it up before so I took an external 500gb HD to use for that....freshly formatted NTFS I assume Windows Backup is just windows version of Time Machine. I set it to back up system plus files. I thought the process was taking a long time so I let it go overnight. When I got up it told me there was not enough space!! wtf?? Ah, the annoying windows os strikes. Anybody know why 'cloning' 320gb onto 500gb's of free space is making windows bust my balls here? Thanks edit: The only thing I can think of is when In formatted the drive I kept the 'allocation unit size' to default. I'm assuming this is maybe block size...choices are from 16k to 8192k. Maybe this is the reason? Whats the default size? What should it be set to?