I also referenced this dated post: Dell laptop…
This is for a Windows 10 Dell Precision Workstation.
It has operated without issue for several years.
Thought I would ask in the event others have seen this in different ways since the post linked above was created.
My PC changed from Extended Display to Duplicate Display un-commanded. After that happened Device Manager showed 4 'Generic Non-PnP Monitors' and 1 'Generic PnP Monitor'. These manifest as shown below:
As I was trying to solve this yesterday, the system kept adding more of the 'Black' display icons to the Control Panel applet until I got up to 7 displays. I actually only have the laptop LCD and 2 external monitors.
When all else failed to resolve the issue (after consulting with the contracted tech support) I performed an image rollback to the previous day and the problem resolved, but only temporarily. This morning it did another un-commanded change to Duplicate Display mode and added the generic monitors back in. As soon as I switched back to Extended Display mode the following showed in the applet:
In addition to any suggestions, I'd like to ask if anyone can concur or rebut the following:
Since I reloaded the image and it was initially OK, then did the un-commanded display mode change, I draw the conclusion this is not an OS problem, but rather a hardware issue.
Best Answer
I'm certain the 2 responses by Mr_Moneybags and solomon219 are legitimate solutions for those situations and should be useful for those in similar contexts. That last post reminded me that I should post what eventually solved my problem.
The Dell Precision Workstation BIOS settings has a menu for Video with a submenu for Switchable Graphics. In that submenu is a checkbox for 'Enable Switchable Graphics'. Mine was checked on; I needed to check it off.
After that, the extra monitors immediately disappeared and have not returned and the Device Manager display was corrected as well.