USB 2.0 Display adapter with Windows 7


I am using a USB 2.0 Display adapter with Windows 7

It seems to work on and off at random, when it stops working Windows reports that an “Unknown Device” has malfunctioned.

I know it means the USB 2.0 Display adapter, as if i unplug it, and plug it back in it says it again…

The device status says “Windows has stopped this device because it has reported problems. (Code 43)”

Thanks for your reply,

Yes this is a Plugable adapter.

after chaning the USB cable it seemed to work when it found the device (no more unknown device), however after waking from hibination the device can no longer be found and the green LED goes out. all other USB devices come on as normal.

Device is plugged in to a USB 2.0 Port on the back of the computer, no hub.


Hi - We may try a thing or two more, but it’s sounding like a hardware problem. Please email us direct ( so we have your contact info, and we’ll get you fixed up. Thanks for your patience!

I’m having the exact same problem as gillbilbert. Started on Saturday when I lost power for a couple of hours. After power was restored, my Plugable UGA-2K-A would not fire up. First reboot did not help. Second reboot did and it came back up and was fine. Today, the Plugable seems dead; no light and just shows as Unknown Device in Device Manager. Tried all the suggestions above to now avail. Should I just email What details should I send?

Hi Bret,

It’s possible, but not likely, that the power outage could have played a part. First, try this:

  1. Disconnect both USB and the video cable from the adapter
  2. Connect USB between adapter and computer, while the computer is on.
  3. Finally, reconnect the video cable between monitor and adapter

If the video cable is DVI, this may reset things and get back to a good state.

If this doesn’t work and it looks like the adapter has been fried, just email contact info (address, phone, and email) to, and we’ll get you fixed up.


Thanks Bernie, your procedure did the trick. Problem is I am having to repeat this procedure every couple of days. Prior to the power outage I never had a problem. Does frequently needing to follow this procedure indicate a problem with the Plugable device?

Some more details of my setup. I am using the Plugable with my laptop (Lenovo ThinkPad T61p) through a port replicator. I have Windows 7 Pro x64. The problem occurs when I am redocking the laptop. Again, prior to the power outage the Plugable would be seen as a USB device and after a few seconds the monitor would come on. This was working for about a month. After the power outtage, this only works about half the time. The other half I must follow the above procedure (not onerous, but a pain).

Hi Brent,

Another possible workaround is to use a VGA cable, instead of DVI. Given the behavior, that should also sidestep the problem.

But also feel free to contact us, as you’re within the warranty period, and shouldn’t have to put up with any trouble … even mild pains :slight_smile: