I'm trying to see where all my hard disc space is going and I found a program called Treesize which shows you where the space is being allocated. I found a couple of files that are about 2.5gb each but have no idea what they are, I'm guessing some of you guys will know. What the hell is this? (also can I delete it?) On a side note. Do I need to keep windows.old on my computer? What purpose does it serve?