I have an HP Pavilion Desktop that has 1 VGA port and 1 DVI input. My primary monitor only works with the DVI, so I had to use the VGA port, along with a analog-digital converter box and a separate HDMI cable. I have everything set up how I believe it should be, however when I attempt to extend the desktop across the two monitors, I only get video from the DVI monitor. I can view either one by itself (although the smart TV will only display a resolution of 1024x768 when by itself) and I can duplicate the desktop with no problem. The only issue is with extending the desktop, which was my entire purpose for buying a smart TV. I might mention that this is a Philips Smart TV.