*Difficulty Level: Advanced Users
If you performed an upgrade installation from Windows 8 or Windows 8.1 Preview most likely that’s the reason you are reading this post now. Apparently, there has been numerous accounts on Intel GFX issues with AMD’s Hybrid GFX drivers for Notebooks and Laptops that the Screen Brightness got stuck at a High or Low Setting without any ability to adjust or toggle the slider using both the Management Function (Fn) keys or from the Display Settings of Windows.
Techie Note: The steps that I will provide in this post requires that you are able to navigate and understand what Display Drivers are and the Registry. If you have a faint heart I do not recommend that you continue and rather stop right here and seek for assistance with your Notebook’s Manufacturer or continue with a Clean Installation of Windows and download all drivers from their OEM support site.