Even though Microsoft has officially ceased their support of Windows XP, a large percentage of PC games still supported the OS as there are people out there who just never decided to upgrade. Vista wasn’t the most appealing option to move to, and many systems built around the time XP came out probably would have a tough time doing Win7 justice let alone running a game on the OS.
The support of Windows XP for gaming looks to be coming to a close, as one of the biggest games of 2013 will support Windows Vista and 7 only due to moving to DX11 support. The game is Call of Duty: Black Ops and they made the announcement on their website:
Can I run the game on Windows XP?
No, sorry. Since we upgraded the engine to use DirectX11, Windows XP is no longer supported. It requires Windows Vista or later.
Black Ops II isn’t the first game to drop XP support, but it’s the first game from a major publisher to do so and it’s the first really high-profile game to do it. R.I.P. Windows XP, you never sucked as much as Vista.