Windows 11 · Windows
Fix Windows Not Detecting a Second Monitor
Source-checked About 10 minutes
Answer
Connect and power on the display, then open Settings > System > Display and choose Detect under Multiple displays. If it remains missing, check the cable, input, and manufacturer guidance before changing drivers.
Check the cable and input
Confirm the second display is powered on, connected to the PC, and set to the input used by its cable.
Open Multiple displays
Open Settings > System > Display and expand Multiple displays. The section is collapsed in the image.
Detect the monitor
Select Detect. If Windows finds the monitor, press Windows + P and choose Extend to use both screens, or Duplicate to show the same content on both.
Identify and arrange the displays
Once Windows detects both screens, select Identify to match each on-screen number to its physical display, then drag the displays into their real positions and select Apply.
Test another cable or computer
If the monitor is still missing, test another cable, video port, or computer one at a time. If it also fails on another computer, follow the display manufacturer's guidance.
Video walkthrough
If it does not work
- If Windows sees the monitor but it stays blank, press Windows + P and select Extend, then verify the monitor input and a resolution Windows offers.
- If Detect does not find it, disconnect docks, dongles, and adapters, then test a direct connection and another cable. A second external monitor can also exceed the graphics adapter's supported display count; check its manufacturer guidance before changing drivers.
Sources and verification
Checked against official documentation on . Scope: Windows.
Follow the linked first-party guidance if labels differ after a platform or app update.