What to do first
Reconnect the cable, select the correct monitor input, press Win+P and choose Extend, then use Settings > System > Display > Detect. Move to graphics-driver checks only after the physical path is known.
Display and monitors
Second Monitor Not Detected in Windows 11
When a second monitor is not detected, first determine whether the monitor has power and the correct input, then check whether Windows sees the display.
Quick answer
Start with the reversible checks
Why it happens
Why this problem appears
A second display can fail because of a wrong input, unsupported adapter, loose cable, projection mode, dock firmware, or graphics driver state.
Step by step
Safe troubleshooting order
- Turn on the monitor and select the HDMI, DisplayPort, or USB-C input actually in use.
- Reconnect both ends of the cable and test a known-good cable or port if available.
- Press Win+P and choose Extend, then open Display settings and select Detect.
- Restart the dock or adapter and connect directly to the PC to isolate the accessory.
- Update or roll back the graphics driver if the display disappeared after a driver or Windows update.
Safety note
Know when to stop
Protect important files before resets, driver removal, account changes, or recovery operations. If the symptom points to hardware, repeated software changes can make diagnosis harder.
FAQ
Why does Windows 11 not detect my second monitor?
The most common causes are the wrong monitor input, a loose or unsupported cable or adapter, a projection mode setting, or a graphics-driver problem.
Does Win+P fix a missing monitor?
It can fix a projection-mode issue, but it cannot repair a bad cable, failed adapter, unsupported output, or monitor hardware problem.