>I found an entire game I had forgotten about 7 years ago that was still using 70gb of space.

How? Why? It should show up in add/remove programs in control panel. Also, what kinda gamer would have been playing 70GB games 7 years ago, and/or never have reinstalled Windows or changes hardware in that time?

I think Treesize is better for Windows than WinDirStat these days.