I just fixed one like this but it was user error. They didn't know the onboard desktop DVI port would be disabled when they installed a new PCIe video card. There is no option to keep it enabled so we used the second video port (HDMI) on the video card and latest drivers.
I have connected two DELL E2210 monitors to my pc (running Windows 10) using two DVI-D cables plugged into the DVI-I ports on the PC. However the second monitor is just a blank screen. In the display settings panel it shows two monitors detected, but only one is actually displaying anything.
Having looked in the NVIDIA control panel, it seems as though the connection between the second monitor and the pc is listed as VGA (despite the fact that they are connected via a DVI cable), so I think the issue could be related to this.
I would appreciate any help you may be able to offer.