Yes, there is a 64bit Vista install on it, I right clicked the hdd in My Computer after I installed it on the second connection and after I right clicked I clicked format, but it could not format the drive, then I clicked compress not knowing what I was doing, and now it does not show up under My Computer. I am not sure what to do now. It will work out eventually, but for now, no dice. Not sure how to fix after it got compressed. Any other input would be appreciated.