I've got the same problem. Nearly the same story, I had Vista 32bit, everything was great, today I installed this Windows 7 and it seems that the system can't recognize my video card (Radeon 3650). The device manager shows me "Standard VGA Graphics Adapter" under the "Display Adapter", although I've got my radeon connected...
I understand that people had problems installing drivers with Windows 7, but yet thier system still recognized their video cards...this case is different. Maybe it has something to do with the motherboard?
Any help will be welcomed, thank you