Installing Windows 7 pro on a relatively new computer, I have used the "rollup" to get more-or-less up-to-date and noticed as it was installing that the disk was nearly full. 110 out of 120 Gb used. This makes no sense, as the Windows directory is only 15 Gb. I have copied some games onto the drive, but those are only another 30 Gb. Everything else currently installed is negligible, only a few more Gb. I should have over half of the disk still free. I run a utility called TreeSize and it shows 57 Gb of files in the root directory. That's the correct total of space used. Running chkdsk finds no problems. But there is a HUGE problem. Where did the other 53 Gb of my disk space go?