Just like past updates, some users have also reported brightness issues in the current latest Windfeature update. Brightness Issues In Windows 10 20H2 Update So, I hope this might have helped you out if your desktop’s or laptop’s brightness is not changing. You can check it by increasing and decreasing the brightness of your PC.
Now your PC will install the selected driver and your Windows 10 brightness control issue will be solved.
Here you can also go to your manufacturer’s website to manually check if there’s any driver update available. Now, you need to continue with the next step.
A buggy GPU display driver living on your machine could be the reason why you can’t adjust brightness on Windows 10.