I currently have a PCI-Express video card which supports my dual monitor setup with 2 outputs. I want to add a third monitor via a PCI slot, which I already have a video card for. When I plug the video card into the PCI slot, it disables the PCI-E card. I can hear the sounds as Windows boots up, but get no video on any of the 3 monitors. When I unplug the PCI card, everything functions as normal.

Is this normal behavior? Is it specific to each different motherboard?

  • I've been struggling with the same problem. It seems to depend on the bios. On my current machine (Lenovo IdeaCentre K), as soon as PCI-E card is added, the on-board card disappears without a trace (nothing can be seen in Device Manager). On some other machines, everything worked right away. I even tried installing an old PCI video card, and it did not work alongside the PCI-E (I can use either one or the other, but not both).
    – dbkk101
    Aug 22, 2009 at 8:56
  • That's my problem as well. I'm running a desktop, though. I did find an option in the BIOS, but it was already set to PCI-E. I added a 2nd PCI-E card, and was able to get the 3rd monitor running, but the color was all off. I'm thinking now I might have a bad card... Sep 11, 2009 at 13:33

2 Answers 2


There might be an option in your BIOS to say which video card should be initalised first, although it's possible that went away when AGP died.


Putting a video card in the PCI-E slot automatically disables the video cards on the PCI slots, including the on-board video card.

This, as far as I have ever heard of or dealt with, is just "the way it is" with PCI-E video cards.

Most Dell's, when you boot, will tell you as much. A firmware update doesn't help.

I wish I was wrong, but low-profile, 3 monitor, pci-e, windows xp has proven to be illusive.

It is something about the clock synchronization and differences between how the buses work on pci and pci-e.

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