It was mostly used on workstation machines that contained hardware similar to servers (and thus had drivers even dating back to 2000 era). OEMs didn't give it much attention for consumer machines because they believed the initial shipping estimates of Vista provided by Microsoft. Then Windows security became a massive internet degrading problem, and Vista was very delayed. OEMs still avoided XP 64bit and the consumer world got to experience the full pain of hitting the 4gb barrier.