I have 2 monitors, one VGA, other DVI-D (Single Link) and I'm trying to set them up as dual monitors. However, when I connect them both, only the VGA one works. If I disconnect VGA monitor, the DVI-D gets the signal, but then when I reconnect VGA monitor, the DVI-D goes into "No signal" mode and the VGA one works again.

When both of them are connected at the same time, I can hear plugged- and unplugged-device sounds coming out continuously in a loop (as if the DVI-D monitor tries to connect - makes connected sound - but then fails and makes disconnected sound).

In the display settings, the DVI-D monitor gets detected, after 1-2 seconds, it goes undetected then gets detected again, then goes undetected again and it goes in this loop forever until I unplug it.

So in short:

  1. Is it possible to have dual monitors, one VGA, one DVI-D?
  2. Why does my DVI-D monitor get detected, after 2 secs goes undetected, then detected again, then undetected again (and the loop just continues forever ...)?

Thanks for any help.


VGA monitor: Samsung LS24A450
DVI-D (Single Link) monitor: HP LP1965
OS: Windows 8.1
Display -> device: Intel(R) Q45/Q43 Express Chipset
Display -> Drivers -> Video driver version:
Display -> Drivers -> Main Driver: igdumd64.dll, igd10umd64.dll ...
Driver model: WDDM 1.1
  • Please specify brand and model of all devices (monitor and display card), and video driver version. – AndrewQ Apr 28 '15 at 12:22
  • The answer to the first question depends on your hardware. There isn't enough information to explain the behavior in the second question. – Ramhound Apr 28 '15 at 12:22
  • I have added some info, do you need anything else? – leopik Apr 28 '15 at 12:31
  • What motherboard / PC model are you using? – Scott Chamberlain Apr 28 '15 at 13:21
  • The computer is Dell Optiplex 780 – leopik Apr 28 '15 at 13:26

Your hardware is pretty old (c. 2008), and it somewhat predates commodity dual monitor support. Q43/Q45 has an Intel GMA X4500 adapter if it's using on-board graphics.

You neglected to list the make and model of the computer or motherboard, but as far as I can tell that adapter does support dual monitors in some configurations. It depends on the precise implementation by the system or motherboard manufacturer, so you should reference their configuration documentation, even if it's for Windows XP or Vista. Some people report that the adapter can drive one VGA port or one DVI port but not both, and dual monitor support requires the use of a DVI splitter (it's not clear what they're doing, however, and be warned that "splitting a DVI connection" sometimes means "clone/mirror only").

You may also run into video memory issues. Since it's shared with system RAM, some systems allow you to limit video memory in the BIOS. You should make sure that memory allocation is as high as possible.

I'd also recommend getting the latest driver from Intel.

If none of that works, you can get a video card for about $30 that can drive 2 monitors very easily.

  • Thanks for the good answer, but I'm not quite sure what I should try now ...My computer is Dell Optiplex 780, I tried to look for the motherboard make/model, but I can't find the information. – leopik Apr 28 '15 at 13:30
  • Ok, after watching a video Dell OptiPlex 780 inside, I guess the name of the mother board is as well Dell OptiPlex 780 youtube.com/watch?v=qk9MUAiWiLM&t=55s (I have set the time where you can see the information on screen) – leopik Apr 28 '15 at 13:33
  • @user1680977 Make/model of motherboard is only useful if you build the PC yourself. What does your system look like? The one on the left is an ultra-small, the middle is a small form factor, and the right is a standard mini tower. If you're ultra-small or small form, you're looking at probably $100 for a video card with dual dvi. If you're the mini tower, it's $30. – Bacon Bits Apr 28 '15 at 13:43
  • It's the biggest one, the one on the right. So the only way of achieving what I want is to buy a new video card? – leopik Apr 28 '15 at 13:51
  • @user1680977 It's still not clear if that's the only way. Searching around, some people have needed to get another card, some people are using a DisplayPort and VGA just fine (not sure if your system even has a DisplayPort port), and some people have said they've used a splitter (although they might already have a second video card... again, it's unclear). Dell is notorious for changing hardware without changing the model. A video card will solve the problem (but be sure to get one capable of dual output) but I can't say for sure if it's truly necessary or if there's another problem. – Bacon Bits Apr 28 '15 at 14:15

Please check the official intel guide to dual monitors:


if you meet the requirements, depending on your desired setup, choose either the clone configuration or extended setup configuration.

Also note that in some situations, only it's supported DVI-D only, not DVI-I.

  • Thanks for the answer. I do meet the two requirements and I chose extended setup configuration. But the problem is that when I connect DVI-D (Single Link) monitor, I don't have time to make any changes because I can see it in the display settings only for 2 seconds before it disappears, then again pops up for another 2 secs and then disappears again. In the second point of my question I describe this loop-like behavior. – leopik Apr 28 '15 at 12:48

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