When I turned my computer off last night, I had roughly 102GB free on my 1TB hard drive. When I turned my computer on tonight, I only had 85.1GB. Using Space Sniffer it found that I was supposedly using 715.3GB out of the 931GB available. Also when highlighting all of the folders on the drive and clicking on Properties the Size on disk is 715GB. This should mean I have 130.6GB free. Is there any way to get this space back apart from formatting the drive.