On my iMac I have a partition with Windows 8 (damn).
Basically I use it to... nothing, maybe play sometimes, and It's difficult to get some updated drivers to test a game or cool benchmarks... until now.
NOTE: Also applies to Windows 7 or 8 computers, whether desktop or laptop especially, who are facing more problems.
I found an ATI drivers offered to install it without complications. You can also install the Intel drivers too if you have it, which is essential today.
Link: Leshcat's Catalyst
Link: UnifL manual