ExtremeTech did extensive tests last week to discover how well Windows 7 runs a wide variety of games, going back as far as the 11 year old Quake II. In total, the site tested 22 games on the first public beta version of Microsoft's next Windows operating system. You can check it out over here.
The site concludes there's still some work to be done, but overall they encountered relatively few problems, even with some of the older games.
Despite some of the issues we encountered, we're pretty impressed overall with how well Windows 7 ran our games. Still, there are some issues to be worked out. While most Games for Windows titles—GRID, Company of Heroes, Sins of a Solar Empire— worked fine, we were quite surprised at our problems with Fallout 3.
It's not so much that the game launcher on the DVD crashed—that may just be a minor bug. It's that the game didn't actually install into the Games Explorer, even though it's the only place from which you run the game. Sure, you can dig into your Program Files folder to find the actual executable, but no user should have to do that.