Hi mfb,
Welcome to PCHF!
Does this help in any way?
1. Plug-in PCI card - with VGA cable plugged into the onboard graphics, boot the machine into Windows. Check in Device Manager that the PCI card was detected under Display Adapters. Windows will either have installed it automatically or will come up with an add new hardware wizard. You will see an exclamation mark next to the PCI card in Device Manager, it is meant to have this next to it.
2. Restart the PC and go into the BIOS, under Boot Options (Main Menu), change Primary Display to PCI VGA. Save & Exit. (VGA cable must still be plugged into the onboard graphics). You will not see the post screens being displayed (because its looking for the PCI card at this stage) but you will see a display when it gets to Windows.
3. Go into Display Properties - Settings tab. You will see pictures of two screens, one is greyed out. Right click the greyed out one and click on attached. Right click it again and click on Primary.
4. Then right click the non-greyed out screen and remove the tick from Primary, click on Apply. The screen will go black, plug the VGA cable into the PCI card, all will now be working ok.
Let us know mate.
(from
http://www.fujitsu-siemens.co.uk/rl/.../ProPCfaq.html)