This seems like a relatively common problem but I couldn't find exactly what's wrong with this system. A BSOD appears after about an hour or so of normal use. It seems that some "win32k.sys" file is causing it to crash. I don't know what this file is exactly so I've been unable to diagnose the problem. I have the minidumps attached. If someone could give them a quick read, that would be great. Thanks!