I already know that the estimated GB amount shown will always be less than the actual amount. But, yesterday I cleared off a bunch of files, and when I finished, it said 340 GB remaining. Since then, I haven't downloaded anything, but currently, it is saying 333 GB. This isn't the first time this has happened, and after a random period of time, the missing space shows up again, but then it just randomly disappears again. Why does this happen? My OS is Windows 7, and this used to happen on Vista also. I don't think it used to happen on Windows XP.