You have to have a ATI card.

 

You can activate your account on a pc with a ati card and use it on a pc with a nvidia card:

 

steam://hardwarepromo/305

what is the registery key that steam puts to see if uve done it on one machine

You're late. I posted that like a week or so ago.

Sweet. I wonder why they are doing that though.... :ugh:

to try and make a profit of of their sponser?? ati buttseckzs valve.