Windows – Desktop not recognizing second monitor plugged into VGA port

amd radeondell-vostromultiple-monitorswindows 7

I've got a Dell Vostro 470 with an AMD Radion HD 7570 graphics card.
On the back of my computer, I see a VDI port (looks like it is added as extra) and a VGA port.
The primary monitor that I bought with the desktop pc is attached to the DVI port.

Now I've got another ACER AL1721 monitor that I want to attach as a second monitor, so I plug it in into the VGA PORT but nothing happens ("no signal").
The screen resolution window doesn't show a second monitor nor does the Catalyst Control Center.

How can I make this second monitor work/recognized.

What I have tried

  1. Click 'detect' on the screen resolution window and Catalyst Control Center
  2. Tried the second monitor on a laptop, works
  3. Restarting computer
  4. Updating AMD driver (not sure if I updated correctly, manually searched for an update)
  5. Went into my BIOS & turned on 'Intel Multi-Display'

Best Answer

This is because you are plugging your second monitor into the onboard graphics and not into your video card.

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On the back of your computer where you have your DVI connected is the graphics card (green square). You have your second monitor plugged into the motherboard (red square).

In order to plug in your second monitor as VGA, you will need a second DVI port (most graphics cards have two, it should be next to the DVI you are using) and a VGA to DVI adapter.

A second solution is to get a DVI Y splitter which will take two DVI inputs and turn them into one DMS-59 input which is supported by most modern video cards.

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