I ran Disk Cleanup to cleanup some crap. When I ran it, before loading up the main screen, it locked up saying "Compress Old Files" at the bottom. Now, I quickly exited and later on, tried it again. It still locked up but this time I kept it on longer to see if it would go on by. I noticed my C rive gain an extra .01GB so I quickly exited out again. I then went into the registry and deleted the "Compress Old Files" branch and it worked fine.
My question is, did this analysis of "Compress Old Files" actually compress some of my files? I seriously doubt it did as it was just analyzing my data and the .01GB gain in space could've been completely coincidental, but something keeps nagging me that it has. How do I check for this?
Are you certain that it locked up? That task sometimes takes a while. At the point you describe, the utility is looking for files that you haven't used for a period of time (something liek 50 days or so). If you notice, it says Scanning: Compress Old Files. If you have a lot of files that you haven't used in a while it takes some time. I'd say try it again and let it sit for a few minutes.
Compressed files are usually blue. So if you look around and see files that are blue (the text) then they are compressed.
I really don't think it did. It won't compress until it scans them first. Then you have to check the box to compress them (once the utility loads) and then run then click ok (to start the compression). I'm sure your files are fine.