I have two large Westinghouse TV monitors with HDMI and VGA inputs. I have been using my computer on one Westinghouse for a long time, but can't seem to be able to connect my second monitor to my computer to extend or mirror the display. (Yes, I have clicked on "Extend these displays" in the display control panel.)

There are two AMD Radeon HD 7700 video cards installed on the PC with Windows 7 64bit.

When plugging in two HDMI cords to both video cards, only 1 monitor is displayed. When both HDMI cords are plugged in and no VGA cords are plugged in it says "2. Display device on VGA". When I unplug the second HDMI cable and try one HDMI one DVI>VGA, it still detects it as VGA but it won't display on my tv with the VGA input connected, it still just displays on 1 monitor through HDMI. I have tried two VGA setups and that didn't work. Still just one monitor.

I went to AMD.com to update my drivers and they had me download some autodetect driver software which installed on my computer and forced a restart. During the installation both of my monitors turned on and I saw a cursor work on one screen, then that screen would turn off, the cursor would then turn on on the other screen, shut off, and the cursor would keep going back and forth like that every 10 or so seconds.

Now that my PC is back up and running, my cursor can move off screen as if it's moving onto the extended display. But the video output is not reaching my second monitor.

I tried a Google search for other people that are also unable to get their second monitors setup and couldn't find a solution that fixed my system.

Is there anything I can do to possibly get these 2 monitors working and do you know if you can identify the problem?

Here are some screenshots. And thank you.

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  • 1
    Do you have Crossfire enabled in the Gaming tab? – JGroven Mar 2 '18 at 0:18
  • yes AMD Crossfire and AMD Crossfire Logo are both set to "On" – Michael d Mar 2 '18 at 0:22

Windows uses one of available graphics cards for DWM rendering. So you need plug both monitors to one graphics card and then you can normally render DWM on second screen. Notebooks don't have this problem, because both built-in screen and HDMI output rendering on the same graphics card.

  • Wow, you're absolutely right. That worked. I can't believe I missed something that basic. Thanks Dengr! – Michael d Mar 2 '18 at 0:56

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