When I view available disk space in the hard drive properties for my C drive it says 20giga bytes are used. If I go into my hard drive and select all of its contents it shows around 15giga bytes of used space. This happened to me one other time and the only way I could fix it was to reformat the drive. I don?t want to reformat my C disk again. I have used defrag and disk cleanup and they don?t help. Anyone have some ideas? Anyone else ever had a problem like this?