A fundamental requirement for any gaming PC is that it should be able to run all of your favourite games. Even though it was replaced some time ago, Windows XP remains the best choice for compatibility. Just about every major new release is written to run on XP, and there's a good chance that it will run older DOS games, too. (Read 'Which Windows is best for gaming?)
It's a similar story when it comes to joysticks, gamepads and other accessories. Most new hardware comes with drivers supporting XP as well as Vista. XP users also have access to a wide range of older kit that may never see drivers released for newer OSes.
This doesn't mean that Windows Vista users are deprived, of course. You can still run a plethora of old games – we've even found one or two ancient examples where Vista proved more compatible than XP – and there's no shortage of compatible gaming accessories.
What's more, Vista and Windows 7 add support for DirectX 10 gaming – a graphics and sound standard that can deliver new effects, better image quality and should improve performance in compatible games (assuming you've got a DirectX 10 graphics card).
3D POWER: Windows 7's gaming performance is already impressive, and it's only going to get better
We say 'should' because Vista has performance issues and doesn't make the best of RAM – a real problem when you're playing more demanding games. Does Windows 7 improve the situation? Our first tests didn't give clear answers: Windows 7 managed the best frame rates when we ran Unreal Tournament 3, but XP won out in our Company of Heroes tests (a shame-faced Vista came last each time).
What we can say is that Windows 7 performed really well for a pre-release version and should be faster still by the time it's released. The Windows XP advantage also tends to fall away as you use faster hardware. So, if you have a decent mid-range PC, Windows 7 would marginally be our preference for gaming, although XP still performs remarkably well.
XP: 4 / 5
Vista: 3 / 5
Windows 7: 4 / 5