So I was looking at my single hard drive I have installed and it says that I have 360gigs free of 600gigs on the HD, I have looked at all of the files with in the C drive that are visible and the approximate total I came up with was 150gigs which means I SHOULD have about 450gigs free not counting the OS, and yet, I cannot image the OS to take up 100gigs of free space. The only thing I can think of, when I was having troubles installing windows the first time I didn't realize that my comp wouldn't boot because it was looking for a floppy so I attempted to install windows several times. Would that be why I have lost so my HD space? and if so, how to I delete the obsolete versions I'm not using?