I have a WinXP box (Asus P4C800-E motherboard) that had two Nvidia video cards (6800 GT & 5800). The 5800 blew out so I bought the UGA-165 as a replacement.
The UGA-165 is hooked up, drivers are installed and the green LED on the UGA-165 is illuminated, but the second monitor acts as if there is no video signal.
WinXP has both Nvidia and Plugable drivers installed. The Display Properties window shows that it’s configured for two monitors (primary using Nvidia, secondary using Plugable driver). 2nd monitor has the checkbox checked to share desktop. Still no video.
I’ve tried swapping monitor, DVI cables, removing Nvidia drivers and installing older versions (May 2011 version).