Two video cards, an ATI and a NVIDIA and vista in a Mac Pro

[iTris]

Hi,
A friend of mine bought a Mac Pro with the standard configuration, that is with a ATI 2600XT. He also bought a GeForce 8800 GT 1Gb for use with vista only. We tryed to flash the card so it would work on the Mac OS side but the eprom size was only 64KB.
So the idea would be to have both card in the machine, the geforce for windows and the ATI for the mac. The problem is that windows vista doesn't accept 2 video card from two different vendors ( see http://www.microsoft.com/whdc/device...imonVista.mspx for more infos). So we are trying to disable the ATI in vista, but couldn't find a way. Disabling the the video card device in device manager does not solve the problem.

Does anyone has an idea on how we could get the nvidia to work while the ATI is still in the machine ? This way my friend could use the Mac side without opening the machine every time.