Windows 10: Extending Monitor Display

I am using a television as a second monitor, but when I extend the display, it gives me a "not supported" box. The main monitor however is fine, but all the windows and icons disappear, and I am left with only the taskbar on the screen as if my main monitor has become the second monitor and the tv has become the main monitor, but I am unable to access anything on it as it is "not supported" and any window I try to open on the main monitor does not appear. I am able to duplicate the display just not extend it. I have tried uninstalling and reinstalling drivers, as well as changing the resolutio

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Extend Display to second and third monitors

Hi Ian,



Thank you for writing to Microsoft Community Forums.



I appreciate the efforts taken by you in resolving the issue. I understand that you are unable to extend the display to second or third monitor. I’ll certainly assist you with the issue.



However, it would be great if you can help us with the details requested below:

• What happens when you try to extend the display?
  
• Do you receive any error message/code?
  
• Are you aware of any changes made to the computer recently?
  
• Which build version of Windows 10 is installed on the computer? To check type:
  winver in the search bar on the Taskbar and hit
  Enter.
  
• What is the make and model of the laptop?
  

Ideally, to extend the display we can use the shortcut Windows logo key + P, and select
Extend from the menu.



I would suggest you to refer the troubleshooting steps mentioned in the article

Troubleshoot external monitor connections in Windows 10 and see if that helps.



For additional information, see
Set up dual monitors on Windows 10.



Let us know the results.



Regards,

Nikhar Khare

Microsoft Community - Moderator

 

Unable to extend monitor display

Hi Jay Jap,

thanks again for your reply.

I checked the screen resolution settings through windows and then through the Nvidia graphics cards.

Windows detected both monitors but Nvidia settings didn't.

I downloaded and installed the Nvidia drivers again and it's working fine. Simple solution, not sure why I had to install the drivers again? But thanks for your help, your suggestion to check if the monitors were being detected prompted me that it had to
be a graphics card issue.

 

Unable to extend monitor display

Thank you for the information L L33_01. I would like to know more information so that we can pinpoint the cause of the problem:

• May I know what kind of connection are you using(HDMI, VGA, etc.)?
• If you go to the Screen resolution settings, does it detect two monitors?
• Also, since the other screen is blank, does it have an error message?

If the connection worked before you perform you reinstall Windows 7, then let us try to clear the multiple monitor configuration of your monitors, and then extend your display by changing your display settings. Here's how:

1. Press Win + R to open a run box.
2. In the Run box, type regedit, and then click
   OK.
3. Locate the following registry subkey:
4. Depending on your machine, it is either: HKEY_CURRENT_USER\Software\Microsoft\MobilePC\TMM or
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\TMM
5. Right-click the subkey, then, click Delete.
6. When you are prompted to confirm the delete operation, click Yes.
7. Exit the Registry Editor and reboot your machine.

Once you are back in, try to perform these steps to extend your display:

1. Open Screen Resolution by clicking the Start button ,
   Control Panel, and then, under Appearance and Personalization, click
   Adjust screen resolution.
2. Click the drop-down list next to Multiple displays, click Extend these displays, and then click
   OK.

Note: The manual troubleshooting steps above tells you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection,
back up the registry before you modify it. Then, you can restore the registry if a problem occurs.

For more information about how to back up and restore the registry, you can refer to this
article.

Keep us updated.