If brightness is locked in Windows 11, use this order:
- Check whether this is the built-in display or an external monitor.
- If it is an external monitor, Windows may not show a working brightness slider.
- Change brightness by using the monitor’s physical buttons.
- Try the Windows brightness control again.
- Select the Network icon on the right side of the taskbar.
- Move the Brightness slider.
- Or go to Settings > System > Display and adjust Brightness.
- If the slider is missing, grayed out, or does not actually change brightness, update the display driver.
- In the taskbar search box, type Device Manager and open it.
- Expand Display adapters.
- Select the display adapter, then press and hold or right-click it.
- Select Update driver and follow the instructions.
- In Device Manager, also make sure the display adapter is not disabled.
- If it is disabled, enable it.
- If brightness keeps changing on its own or appears stuck because of adaptive behavior, check these settings:
- Go to Start > Settings > System > Display.
- Select Brightness.
- Turn off brightness automatically when lighting changes if that option exists.
- Set Change brightness based on content to Off if that option exists.
- If this is a Surface device, content adaptive brightness and contrast can cause visible brightness changes.
- Go to Settings > System > Display > Brightness.
- Set Change brightness based on content to Off.
- Note: turning this off can reduce battery life.
If the problem started after a driver change, installing the correct graphics driver from the PC manufacturer is the next step after the Device Manager update.