8 Easy Fixes for Dual Monitor Not Detected or Extending on Windows

ByJim Miller

The convenience of using dual monitors on your Windows computer can greatly enhance productivity by allowing you to easily multitask and work on multiple applications simultaneously. However, there may be times when your second monitor is not being detected or extended properly. Don't worry, we've got you covered with these simple solutions to troubleshoot the issue.

Before You Begin

Before diving into the troubleshooting methods, it's important to ensure that everything is in order. Here are some quick tips to consider:

  • Check if your computer or laptop supports dual monitors and if it has multiple display ports.
  • Use the Windows shortcut Windows + Ctrl + Shift + B to troubleshoot the problem.
  • Make sure both monitors are connected to the same Wi-Fi network if you are using a wireless display.
  • Ensure that your monitor has a separate power source, apart from the HDMI or USB-C cable.
  • Check the cables for any damage or wear and tear.
  • Disconnect any peripherals that may be interfering with the connection.
  • Avoid using a splitter as it may not properly extend the display.
  • Double-check that all cables are securely connected and that the monitor is powered on.
  • Refer to a manual or video tutorial to determine if your laptop or CPU supports extended monitors.
  • If the issue occurs after waking your computer from sleep, follow a separate guide for troubleshooting.

1. Turn Off Monitors Before Connecting

Sometimes, Windows fails to recognize the second monitor when it is connected. To resolve this, turn off both monitors and then turn them back on. This simple reboot can help reset the signal and refresh the connection, allowing Windows to detect the second monitor.

2. Enable Extend Option in Windows

By default, Windows displays the second monitor in mirror or duplicate mode. To enable the extend option and project the screen from the primary monitor to the second monitor, press Ctrl+P to open the Project screen and select the “Extend” option.

3. Force Detect Second Monitor Manually

If your primary PC cannot detect the second screen, you can manually force the detection. Open the Windows Settings (Windows+I), go to System > Display, and click on the “Detect” button next to “Detect other display.” This will prompt Windows to search for and detect the second monitor.

4. Check Scale and Resolution

Adjusting the scale and resolution settings can help resolve issues with dual monitor detection. Open the Windows Settings (Windows+I), go to System > Display, and scroll down to find the “Scale” and “Display resolution” options. Select the second monitor and choose a scale and resolution that work best for it.

5. Set Same Refresh Rate

Setting the same refresh rate on both monitors can sometimes resolve issues with extending the display. Open the Windows Settings (Windows+I), go to System > Display, select the display at the top, click on “Advanced display,” and choose a refresh rate. Repeat the same steps for the second monitor and ensure that both have the same refresh rate.

6. Update Display and Graphics Card Driver

Updating the display and graphics card drivers can help fix display-related issues. Open the Device Manager (Windows key + search for “Device Manager”), expand the “Display adapters” and “Monitors” sections, right-click on the drivers you want to update, and select “Update driver.” Repeat this process for both primary and secondary monitors, as well as integrated and dedicated graphics cards.

7. Uncheck HDR for Second Monitor

Enabling or disabling HDR for both monitors can help resolve issues with extending the display. Open the Windows Settings (Windows+I), go to System > Display, click on “HDR,” select the display for which you want to change the HDR setting, and disable the “HDR video streaming” option. Repeat this process for the second monitor.

8. Delete Registry Key

If you encounter the “unable to save display settings” error when trying to extend the display, deleting a specific registry key can solve the problem. Open the Registry Editor (Windows + S > search for “Registry Editor” > run as administrator), navigate to HKEY_CURRENT_USERSoftwareMicrosoftMobilePCTMM, right-click on the sub-key or file in the right window pane, and delete it.

With these easy fixes, you should be able to resolve dual monitor detection and extension issues on your Windows computer. Remember, Windows can sometimes be a bit finicky with multiple monitor setups, but with a little troubleshooting, you'll be enjoying the benefits of a dual monitor setup in no time.