PORTAL 2 WONT WORK

[Nico]

The game will only let me go to the menu if i try to star a game it turns OFF MY COMPUTER !!!!!!!!!!!!!!! VALVE PLZ FIX!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Aurora LukVeil]

your not alone if this is not fixed soon i will go insane plez fix it

[crepaia]

turns off your computer? what the hell are you talking about

[Jerajamz]

There should me a "Me too" button. Just wondering, do you have AMD catalyst? After googling around I've read that might be the problem (Definitely not my computer, it runs anything else fine.)
@Creepyface: The game shuts down our computers when we try and play portal 2, for some reason.

[little_addict]

The latest 20MB Split Screen support update that automatically downloaded causes this headaches. I cannot get pass the Valve/Steam logo screen then I get kicked out to the desktop.
Blimming annoying

[Shweatyballs]

I had P2 running fine yesterday, but then I upgraded to Win8 and now can't get past the steam logo. Boots me out to the desktop with a "Portal2.exe stopped working" message. Serves me right for installing a mobile OS on my desktop i guess...