ATi video card driver will not install successfully!!

[speedv15]

I am currently running on an nvidea video card with teh onboard disabled. i want to install an ati card to use dual monitor with the nvidea and ati. i have both working great right now, but the computer says that there is no ATI driver installed. Therefore, many of the features do not work. i tried installing the new drivers from teh ATi website etc., but it still does not work! any ideas???

[speedv15]

I am currently running on an nvidea video card with teh onboard disabled. i want to install an ati card to use dual monitor with the nvidea and ati. i have both working great right now, but the computer says that there is no ATI driver installed. Therefore, many of the features do not work. i tried installing the new drivers from teh ATi website etc., but it still does not work! any ideas???

[apatosaurus237]

what is the exact model of the card?
to find out do this:
start>run>dxdiag
then click "display" and see what it says under "name" and "chip type"