Even though Windows 7 only accounts for 6% of the global Operating System market, 23% of steam gamers use it.
Download Squad did a study that showed not only what OS gamers were using, but also there processor speed and video card. The average processor speed was 2.5GHz and 65% of the gamers where using NVIDIA graphics cards as opposed to ATi's 30%.
One of the best stats that their study showed was that after just 4 months, Windows 7 (23%) has beat out Windows Vista (20%). Gamers sure didn't like Vista! Then again, who did?
Source: Downloadsquad.com