I bought a new ATI Graphics card after the existing nVidia card packed up but it is not detected at boot so Vista won't detect it either. The card is a ATI Radeon HD2600 1Gb DDR2 AGP card.
The card fan works and system starts up with basic video, very low resolution.
#1 download driver sweeper, then install
#2 uninstall the old nvidia drivers
#3 boot into safemode
#4 run driver sweeper in safe mode, check only the ones that says nvidia
#6 install the the catalyst drivers
now im not familiar with that motherboard of yours, it might need a bios update (god forbid). lets hear other has to say.
Your list of suggestions is for the driver installation in windows. Unfortunately the card is not detected as an ATI card at system startup itselfso it doesn't even make show up in the OS. It seems that the bios or mobo does not recognise the card.
I think the bios update is more applicable and am checking if there are any updates.