Alright alright, guys, listen, guys. Listen.
This weekend I decided to thoroughly format my hard drive. I don't just mean the windows boot default "format" which takes roughly a second. I nuked my hard drive using DBAN (took roughly 8 hours for 300 GB) and reinstalled windows.
Currently I've got 15 GB of space on my system partition and 66 GB on my other partition and IW works flawlessly now. Well, nearly, but nothing related to crashes.
So, my advice, format your hard drive or just clean it up thoroughly. Did wonders for me.