I also have similar kind of a problem.
I am having Pentium 4 processor,Windows Xp OS.
Motherboard is Intel original 845GLLY model as i on-board display got a problem i was suggested to use PCI VGA card .
Now I am using PCI VGA card ,maker intex techonologies (
www.intextechnologies.com)
i have installed the drivers the maker has provided even though the excamalation mark is still shown on Video Controller (VGA Comaptible)
Can somebody help me to sort out this.