Have you looked in the device manager and is the card displayed on there?
if you can see windows then i would say the card is displaying something, do the disk that comes with the card have Windows 7 64 bit drivers on, I think this is a pretty old card, so maybe not.
you might have to got to the ATI/AMD site to download the drivers.
Vista 64bit drivers will also work.
Desktop machine now powered by windows 7 pro 64bit , laptop by ubuntu
On ADSL24 using C&W network.