All my games play fine but one. I can't seem to Play BIOSHOCK on DX10 anymore. It will only play on DX9. I did a driver sweep to clean up my old drivers and uninstalled and reinstalled BIOSHOCK. But the silly game just will not recognize DX10. Am I having a conflict with my GPU and OS? I am sure it's an easy fix, but I can't for the life of me figure it out.
You could try adding -dx10 to the command line. For instance...Make a shortcut to the games .exe file. Right click the shortcut and select properties. Where it says Target: "C:\Bioshock\Bioshock.exe" change it to something like
"C:\Bioshock\Bioshock.exe -dx10". I don't own bioshock for the PC so your command line contents may differ as I am just guessing at your folder layout...However, adding -dx10 to a games target path generally forces the game into that mode. Also, make sure you are running the game as an administrator. Windows Vista and Windows 7 tend to ignore .cfg files if you don't run programs as an admin. Good luck!
If I remember correctly Bioshock had two seperate executables, one for DX9 and one for DX10. If not, then check and make sure that the executable isn't using some sort of compatibility mode. If you are using a shortcut, delete it and make a new one as well to avoid compatilibilty mode issues.
If only one game is doing this and DX9 works fine, its not a GPU/OS conflict -- especially if it worked before. You could go look at ATI's driver notes and see if BioShock is listed as a known issue, which would also answer your question. I'm assuming by latest drivers you mean 9.11