Multiple Monitors: Can I run my integrated video card with a PCIe video card simultaneously?

I have a Dell Optiplex 780 at work, with an integrated Intel 4500 video card. It has a single VGA out video port. I have installed a Sparkle 8400GS (NVIDIA) card in the machine, which has a VGA and DVI output.



I can run 2 monitors using the VGA and the DVI ports on the installed card, but if I hook a third monitor up to the integrated video card, my computer will not boot and gives me a monitor error, prompting me to hook the monitor up to the installed NVIDIA card.



Is there any way for me to activate the integrated card as a secondary card to run the third monitor from?



FYI- The computer is a low profile machine, so the Sparkle video card has taken up both (2 of 2) of the open windows, as the VGA and the card fill the PCI Express slot and window, and the DVI port was installed in the second open window without filling the second slot.



Thanks for the help!|||This won't work because if you use the on-board video the bios will not set the default card to the 8400 and not work at all. It will only use the the 4500. Same the other way around. So in your current setup you can only get 1 or 2 monitors going at once.