FIX - Brightness Controls w/AMD Radeon GPU
Having trouble with the Brightness controls on your Mac and already disabled Adaptive Brightness? Here's a fix for those of you with AMD Radeon GPUs, the latest AMD drivers and Windows 8 or newer.
Found on the Microsoft Community Forums, the fix is quite simple:
- Open the Registry Editor by pressing CMD+R and typing in "regedit", without quotes and clicking OK.
- If prompted, click "Yes" at the User Account Control notification.
- In the sidebar, navigate to "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{xxxxxxxx-xxxx-xxxx-xxxx -xxxxxxxxxxx}\0000". NOTE: The folder that contains all of the x's is an example and yours may be different. You will need to locate the one that references your proper GPU. EG. AMD Radeon 6600M and 6700M Series.
- Once inside the "0000" folder, on the right hand side of the window, locate the keys named, "KMD_EnableBrightnesslf2" and "KMD_EnableBrightnessInterface2". If these keys do not exist, they will need to be created. To create these keys, right click in a blank space on the right hand side of the Registry Editor and click "New -> DWORD (32-bit) Value". Type in the text shown earlier in this step (without quotes) and set the "Value Data" to 0. If these keys did already exist, you can simply double click on them and do the same.
- Reboot computer and enjoy your now functioning brightness controls.
This took care of it for me on Windows 10, but should work in earlier version as well. Feel free to me know if it's not working on your machine!