How to install ATI drivers for DX10 ? Can't install (error)

I have iMac 27" with i5 + ATI Radeon 6770 1GB.
I downloaded drivers from ATI website (mobile/desktop) but mobile doesn't recognise card and desktop finishing installation with error (I can't open error message). I thought that maybe I don't need one, but I checked 3D Mark and I getting error that I need GPU which supports DX 10 (that Radeon should run it without problem). I tried Minecraft and I got nice low FPS (around 15-17)...

There is no big rush as I have PC for gaming but it would be nice to play on iMac as well...

Any idea how to run 3D ??? Oh I have Lion + Parallels 7

 

Facts:

- When Windows is running under Parallels it does not 'talk' directly to the Graphic's card. No matter what card it is, what Windows 'sees' is a Virtual one called something like Parallels Video Adapter.

- Because of the above 'Parallels Tools' install a driver specific for this adapter and there are no other driver you can download from anywhere on the internet that will get a better performance under Parallels.

- Parallels Video Adapter doesn't currently support DX10, hence the 3D Mark message.

- 3D Mark is a benchmark application, the fact that it won't run shouldn't be any reason for worrying, what you should worry is if your specific game or application doesn't run.

- Only running under Bootcamp can Windows 'talk' directly to the GPU.

- OSX comes with it's own graphic drivers for OSX, and Bootcamp drivers for Windows (when running under Bootcamp ). So there's no need to fetch any drivers externally.

- Always install Parallels Tools.