Now, your PC will use your internet connection to download the drivers that are necessary for proper functionality. To check, open Run > Type dxdiag and press Enter > Go to display tab. Click on it to expand and right-click on the GPU that powers your display (internal or discrete). Most of the time, the Windows 10 brightness problem can be solved by simply updating the GPU drivers.
A buggy GPU display driver living on your machine could be the reason why you can’t adjust brightness on Windows 10.
