I've been in contact with Several people from Valves TS, many post looking for help on here and other forums. Couldn't figure it out.
Had to downgrade back to 7, and waseted money on a new OS that I cant use.
Civ5- didn't work
CSS: didn't work
and a few others.
( stand alone installed games worked fine, Origin games works fine )
This is trying it with SEVERAL fresh installs on seveal different hard drives, bios settings, GPU's, etc.
Basically valve just told me that my computer must be broken.
Several people got the games to work on 8.1 but for whatever reason, I cant. My room mate had a similar issue, but he isn't a fan of 8 so he didn't care about going back to 7, I liked 8, but since I'm only on windows for games, I've alot of money wasted because I have a product key I can't use.
( fyi, games used to work on 8, but 8.1 is where the problems started )
Edited by Jixr - 4/1/14 at 8:54am