I've looked at some of the threads with a similar problem, but I only found questions about space decreasing. Mine increases as well, after no action from me, with no files left in trash. When the space decreases, it usually settles around 2-3gb, and when it increases it never goes back up to where it should be. When I restart the computer the number looks accurate (around 10gb at the moment), but it never stays like that for long. I've only noticed this problem a couple of days ago, at a time when no applications were downloaded or removed. I ran a disk check and it came out fine, virus check also. Anyone have any idea what it could be? Please and thank you! Edit: I should add that I have been using Photoshop during this time, and when I did close the program the space increased significantly. However, the number was acting up still while the program was closed (PS wasn't open the whole time I was on the computer).