How to fix the error of the brightness adjustment key not working in Windows 11

However, things get tricky if the key doesn't work anymore or has stopped working. In such cases, you may need to take a few steps to fix the dimmer key not working on Windows PC.

1. Restart the computer

Keyboard problems can sometimes be fixed by a simple reboot. Restarting your computer will reset the keyboard settings and possibly get the dimmer key working again.

2. Clean the keyboard to remove dirt

Over time, dirt and debris can accumulate on the keys on the keyboard. This is especially likely if you use your laptop in a dusty environment. Cleaning the keys can make them more responsive and help troubleshoot the dimmer key not working.

If you do not know exactly how to clean the keyboard, you can refer to: Guide to cleaning the keyboard by yourself, cleaning the laptop keyboard.

3. Make sure the function key is activated

The function key may not work if it is disabled on your keyboard. To make sure it's activated, press the Fn + Esc keys simultaneously . This will turn this softkey on and off. If it is disabled, enabling it will fix the dimmer key not working issue.

4. Run Hardware and Devices Troubleshooter

 

Hardware and Devices Troubleshooter is the next step to try if the above solutions don't work. This tool can detect and fix any hardware and device problems on your computer, including problems with the keyboard. To run the troubleshooter, do the following:

1. Open a Command Prompt window with admin rights.

2. Once you are in the Command Prompt window, type and execute the command below:

msdt.exe -id DeviceDiagnostic

This will open the Hardware and Devices Troubleshooter window. Follow the onscreen instructions and complete the process to detect and fix any problems related to your keyboard and function keys. Once done, you can try using the function key to adjust the screen's brightness.

5. Run the Keyboard Troubleshooter

If the problem persists, you can run the Windows Keyboard Troubleshooter. This troubleshooter scans and detects any problems with your keyboard that could cause the dimmer function keys to not work. Here's how to run the tool:

 

1. Press Win + I on your keyboard to open the Settings window.

2. In the Settings menu, click System > Troubleshoot .

3. Click Other troubleshooters on the next page.

4. Scroll down to find Keyboard and then click Run.

After you complete the steps above, try using the dimmer softkey again to see if the problem is resolved.

6. Update the keyboard driver

Outdated or damaged drivers can also interfere with the operation of the dimmer function keys. In such a case, you can try updating your keyboard driver and see if it solves the problem.

To update the keyboard driver, follow these steps:

1. Press Win + X on your keyboard to open the Power User Menu.

2. Select Device Manager from the list of options.

3. Expand Keyboards , then right-click the current keyboard driver and select Update driver.

 

4. Next, click Search automatically for drivers .

Follow the on-screen instructions to complete the process. After completing this, restart the computer and check if the problem is resolved.

If the Fn key remains unresponsive even after updating the driver, there may be a problem with your keyboard driver. In that case, uninstall the problematic driver and reinstall it. Here's how to do it:

1. Open Device Manager and expand Keyboards section.

2. Right click on the keyboard driver and select Uninstall device.

3. Click Uninstall again to confirm and follow the on-screen instructions.

After performing the above steps, restart the computer to reinstall the driver. When you turn the power back on, check if the function key is working.

7. Turn off Filter Keys

Filter Keys on Windows is designed to ignore repeated keystrokes and slow down the rate at which a key repeats when held down, to help users who have difficulty pressing keys on the keyboard.

However, sometimes it can interfere with normal typing and cause the keyboard to not work properly. To turn off this feature, follow these steps:

1. Open Control Panel.

2. Click the drop-down menu next to View by and select Large icons .

3. Then click Ease of Access Center and select Make the keyboard easier to use .

4. Uncheck the box next to Turn on Filter Keys .

 

5. Click Apply > OK .

Now check if your keyboard is working properly.

8. Scan for malicious programs

If you have downloaded any suspicious files or programs, there is a good chance that your keyboard is having problems caused by malware, spyware or other malicious programs.

To make sure that's not the case, you can check if the file is infected with a virus. You need to scan your computer for viruses and then remove them.

If you are more comfortable with command line tools, then use Windows PowerShell to scan and remove any malicious components from your system. This will help you troubleshoot the keyboard not working properly.

9. Switch to another keyboard

Sometimes the problem lies in the keyboard itself. The keys may be faulty or some other hardware problem that prevents it from working properly. In that case, try using your device on another computer or laptop to make sure that the problem is not with the operating system or software.

If you find your keyboard has problems, it's time to replace it with a new one or have it repaired.