why am I losing more harddrive space than I should be?

hey guys, so I've been noticing that I'm losing harddrive space at a pretty fast rate lately. I thought it was just me dling things but today I installed Prince of Persia sands of time onto my PC and my harddrive space went down from 394 to 389gb. I looked at the box and it said the game took up 1.5 gb space. so how/why did I lose 5 gb of space for something that should take 1.5 gb?thanks! why am I losing more harddrive space than I should be?
you may be able to get a very large portion of that space back if you run a program like CCleaner why am I losing more harddrive space than I should be?
your temp folder is probably filling up
The downloaded game file could take up lots of space, after you install the game delete the file you downloaded.
Or you don't have a static pagefile so Windows resizes it however it wants.
haha I just checked my harddrive space again and I'm at 390 gb now. so strange..
Windows allocates all sorts of stuff for it's own system maintenance. It probably created some temp stuff that it later wiped.

oil industry