Well, now I feel a bit more than stupid Reason for my problems was, that the PCI card was not 100% correct in the slot. Starting up again, Windows 7 found the drivers and off you go...
This PC has an on board Graphic card - An mirage 330 as I remember it here. I have not been able to find a Windows 7 driver for the graphic- All else runs smootly. So, I bought a standard PCI card with drivers and tried to add it. No particular problem with putting it in - It has a PCI slot, but it ...