So I'm at a friend's house today and we want to continue some co-op portal2 today that we started about a month ago. Suddenly portal2 is crashing my machine or freezing before it can even load to title. I've tested other more demanding games (bf3, bc2, ssf4) and everything ran fine. The last time we did the co-op, I was running portal2 on my dual-core with my 8800gtx. Now it's my 8core w/gtx460 that's giving me problems.

I've uninstalled everything steam related, reinstalled steam and portal2 exclusively and yet the problem persists. Thought it might be related to that page file bit I asked about, but messing with that didn't solve anything.

I've no problems with windows at all and everything runs smooth (had network issues, but smoothed that out). Is it just me or is this weird?

Yup, tried that as per friend's suggestion as he read about how nvidia recommended beta drivers for the bf3 beta. installing portal2 from the actual disc right now to see what happens, though I'm not holding my breath.

Sigh. Solved. Took a MODIFIED bios to fix things.

http://www.xtremesystems.org/forums/showthread.php?276698-A-fix-for-Valve-CEG-games-causing-BSOD-on-Bulldozer-issue

Dangerous, I know, but as others have the problem and the source of the "fix" came across as reputable I figured I'd take the plunge. Seems it's something to do with the DRM in steam not playing nice with the AMD Bulldozer toys. Not sure about the fine details. It DOES work, however. I can load up Portal 2 now.