I installed the first 6850 a small number of weeks earlier than I might pay the second. When the second inwards I installed and updated drivers, Then I realized I should have deleted the drivers before you update the drivers for both cards. By downloading the newest version of the package of 11.2 CCC, will be familiar with the two cards and mechanically install drivers for both cards? Then I downloaded driver sweeper and cleaned all the ATI drivers for my pc. Then use the CD that comes with the cards and drivers are loaded base. Finally, I went to AMD site and download the revised CCC 11.2 and 11.01a think. (It was the newest and hot only solution for my card and operating system configuration.) Then go to steam and try to run l4d2 and says that my video drivers are updated and the game does not work as intended. I try to play the game with some very low settings and the graphics are clean, but being wrong. By clean I mean it is not clear, but certainly where they belong. My old computer is running the 4850HD and the graphics were vastly better at it. Then I exit the game and the use of vapor GPU driver update to address the problem of unknown drivers. AMD has me download the driver put together and install it. I l4d2 re-run and low and observe the similar matter. Then run driver sweeper again and reinstall the drivers CD. The game does not recognize it. Then re-run driver fumes form and the problem still exist. The difficulty through that is ASUS Radeon HD 6850 1GBDDR5 ram. So in attendance have to be a problem somewhere with these programs does not recognize the GPU.