Restart everything: Shut down Windows and all your monitors. Then, turn everything on and boot up again. This can often fix your issue. If necessary, roll back driver updates: If your display driver recently updated, it could be causing the issue.
Why won’t one of my dual monitors work?
A buggy, outdated, or corrupted graphics driver can cause problems that may prevent Windows 10 from detecting a second monitor automatically. The easiest method to fix this issue is updating, reinstalling, or downgrading the driver.
Why is my 2nd monitor not displaying?
Check whether the second monitor is connected to a power source. Some monitors have a switch at the back to power on the display. Make sure the correct input (HDMI, DVI, etc) is selected using the built-in controls on your monitor. Connect another working monitor to check if the issue is with the graphics card.
Why is only one of my monitors working?
Using only one external monitor Make sure the cable connecting your PC to your external monitor is secure. Try changing the cable connecting the external monitor. If the new one works, you know the previous cable was faulty. Try using the external monitor with a different system.
How do I get my computer to recognize 2 monitors?
Select Start , then open Settings . Under System , select Display . Your PC should automatically detect your monitors and show your desktop. If you don’t see the monitors, select Multiple displays , then Detect.