How to fix Windows 10 brightness slider not working
Windows 10 has a brightness slider that you can access from the Control Panel and from the Action Center. It can change the brightness of the internal display of a laptop, and the monitor for a desktop. It normally does not work with external monitors that are connected to a laptop.
The brightness slider is also controlled by dedicated keys on the keyboard and they work the same way as the slider does i.e. for internal screens or the main monitor connected to a desktop system.
Fix Windows 10 brightness slider not working
If the brightness slider on Windows 10 is not working, try the following first;
- Use the dedicated keys on the keyboard to change the brightness.
- Open Control Panel and go to Power Options. Use the brightness slider to change the screen’s brightness.
If you’re unable to change the brightness with the above two methods, try the fixes below.
1. Uninstall third-party apps
If you’ve installed third-party apps for managing the video settings on your system e.g. apps that claim to to increase the FPS in a game, or apps that manage display settings, quit or uninstall them. They may be interfering with native Windows 10 controls.
To uninstall an app;
- Open Control Panel.
- Go to Programs>Uninstall a program.
- Select the app and click the Uninstall button at the top.
- Restart the system.
2. Check for driver updates
If your display driver is outdated, and you’re running a newer version of Windows 10, the brightness slider/controls may not work. Update the driver to fix the problem.
- Open Device Manager.
- Expand Display Adapters.
- Right-click the on-board graphics card and select Update Drivers.
- Search online for available drivers and install the ones that are available.
- Repeat for the GPU.
- Restart the system.
3. Toggle Adaptive brightness
Laptops have a sensor that can detect the amount of light in the room. Windows 10 uses this sensor and automatically adjusts the brightness of the screen so that it is suitable for the amount of light in the room. It may interfere with the brightness slider.
- Open the Settings app with the Win+I keyboard shortcut.
- Go to System.
- Select the Display tab.
- Disable/uncheck the Change brightness automatically when lighting changes option.
- Restart the system.
4. Enable generic PnP Monitor
An external monitor appears as a PnP (plug & play) display device. It may need to be enabled before you can control it’s brightness with built-in Windows 10 settings.
- Open Device Manager.
- Expand Monitors.
- Right-click the PnP monitor device and select Enable device.
- If the device is already enabled, select Disable device.
- Click the Scan for hardware changes button at the top.
- Windows 10 will install the monitor again.
5. Edit Windows registry
Try tweaking the registry to get the brightness controls to work.
- Tap the Win+R keyboard shortcut to open the run box.
- In the run box, enter
regeditand tap the Enter key. - Go to this key:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0001 - Double-click the FeatureTestControl Dword value and set its value to 0000ffff.
- Restart the PC.
Conclusion
Windows 10 brightness controls work out of the box for internal displays but not with external displays. If you’re using an external display, consider using Twinkle Tray to control brightness for it.
