I'm using windows 7 (64bit), I have a 500GB C drive and a 1TB data drive. This computer is mainly for music recording/editing and a little bit of video editing. I use the 1TB D drive to store all of my music and video related projects. I have a lot of stuff on that drive, mostly high quality, uncompressed audio files, but with that said, there is no way that I am using the amount of space that windows says I am using. Looking at every folder and subfolder I have on the drive, I am only using 93GB for music and video files, and less than 1GB for miscelanneous files but Windows says that only 38GB of 931GB is left! It should actually be 837GB left. So 799GB just magically disappeared into space?? What's going on? I've had the computer for two years and it has always been accurate with it's free space estimates. I just noticed this last week. What should I do?