I bought it from a German Reseller (OEM for Vista Ultimate and Home Premium). Its meant for the EU market but the key works fine and it even activated.

Had a bit of a problem later , Windows said it wasn't genuine and stuff like that. No matter how I reactivated it , it still says the same (Activation passes though). Finally , I had to call up Microsoft and get it sorted out . It was hassle free and my Vista is genuine once again (Maybe the seller could be right , but I doubt so)