Hello, 

 

On a Dell Optiplex 7400 AIO that was upgraded by us to Win11, we are unable to figure out why the display brightness cannot be changed. The slider on Windows settings does nothing, and Dell On-screen Display (OSD) doesn't seem to function on it. 

 

List of what I've attempted:

 

-updated drivers and bios

-updated windows 11 to latest

-attempted to install Dell OSD 

-verified Windows power settings

Any help would be much appreciated