.... The video card is a GeForce 2 MX. Following the
instructions in the Radeon manual, I updated the VIA 4-in-1 drivers, then
uninstalled the GeForce's drivers (they were the most recent drivers on
Nvidia's site as of a week ago, but I don't know the version number),
then powered down to swap the cards.

Removing old drivers can be a problem. Go to http://Rage3d.com and look in
forums for more info and advice. They should have program there to remove
old drivers completely.

-Kent