Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

One of the developer PC's running Windows Vista Ultimate had the second monitor stop being recognized in Windows overnight. There were no hardware or driver changes at the time, though I have subsequently updated to the latest nVidia drivers (card is NVIDIA GeForce 210).

The non-recognized monitor IS recognized during the boot sequence. In fact, only the "bad" one shows the POST or the Windows loading screen. At some point during Windows initialization after the loading screen disappears and before the logon screen appears, the active monitor switches.

Any thoughts?


When I open the Vista monitor properties window, I see my primary display and secondary display depicted. The primary one is portrayed as the regular blue box, but the secondary one is portrayed greyed-out. I have the option to "Extend desktop to this monitor", the only resolution is 800x600, and all of the advanced monitor properties are greyed out as well. If I opt to extend the desktop, the greyed-out box turns blue, when I then select Apply the screens flash as usual and I'm given the 15 second countdown to accept the new settings and when I do, everything returns to the previously broken state... secondary monitor is portrayed greyed-out again. At no point is the desktop shown on the secondary monitor.

share|improve this question

migrated from Mar 10 '10 at 5:08

This question came from our site for system and network administrators.

Would be interested to know why the question was downvoted for future reference. – Eric J. Mar 10 '10 at 5:23
Agreed. Downvoting without a comment is bad form. – mindless.panda Mar 10 '10 at 5:37
It was probably originally downvoted because it was a question about a single computer's configuration posted on serverfault, which is a site for network/system administration. Superuser is for questions about single computer configurations. – Chris S Mar 10 '10 at 16:50
Hmmm... I reviewed the FAQ for both ServerFault and SuperUser before posting and thought since I'm administering a number of developer machines that ServerFault would be more appropriate. My understanding was that SuperUser was more for "power users". Thanks for the clarification; I'll be sure and post this type of issue on SuperUser in the future. – Eric J. Mar 10 '10 at 17:44
up vote 1 down vote accepted

I had a similar problem where the NVidia control panel was preventing Windows from being able to use the second monitor. Try uninstalling the NVidia drivers and see if Windows can use the other monitor then. If that works, you can either use the default video drivers or try to get the nvidia drivers to play nice.

share|improve this answer
I had previously tried uninstalling all of the drivers and that did not work. On the recommendation of the graphic card manufacturer XFX I downloaded Driver Sweeper from and used that to completely remove all traces of the previous drivers before reinstalling the current nVidia drivers. I'm accepting your answer because it was essentially correct but want to add this additional info in case anyone else comes across this. – Eric J. Mar 13 '10 at 3:27

Just having the monitor disconnected can cause this (I experienced it yesterday).

Enable the second screen again in the driver software.

In my case it was menu Start/Program Files/Catalyst Control Center/CCC - Advanced/Graphics Settings/Displays Manager/<right click> on "Desktop 2"/Enable.

share|improve this answer
This does not work for me. I updated the question to explain. – Eric J. Mar 11 '10 at 17:00

I had a similar problem. Except I'm running 2 cards in sli mode. Monitor stopped showing anything, except during bootup. Ended up logging in through RemoteDektop, removing nvidia drivers, and reinstalling PREVIOUS Version that came with the cards when I bought them. Then rebooted by PC a couple of times and it started working. I'm running WIN 7 on my home machine. I think this might be related to the latest drivers, not monitor or cards.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .