Do you have an NVIDIA based video card?
 

If you do, they have 4 free games on Steam for Nvidia based Gamers...

http://www.steampowered.com/nvidia/

(1 Demo, 3 full versions)

Time to dust off the old Ti550. :pimp

I've got some Nvidia thing in the desktop upstairs, but I don't even remember what it is. It wasn't ATI, and wasn't Intel onboard. Between 6xxx and 9xxx.