I have installed Windows 8 Pro resently, however, I must first explain: When I was using Windows 7, I locked the clock Speed of my A 5750M APU to 3,2Ghz, what was knowingly causing problems with the integrated iGPU, because of the custom change in the bar files I made, making the APU (AMD CPU) not able to switch between integrated and disrete graphics accordingly. This would then cause the bar files to be reenabled after I would use a non game desktop appilication with the hd 8970m, the discrete graphics card. When I was doing this I noticed that after the first Startup after enableing the bar files in that context, the Notebook would shut down because of the switchable graphics Default. ( I know this because the light turn White and red, depending on GPU, and it should have been White after reboot, but it stays red and the Notebook doesnt do nothing except running and not rebooting nor shutting down.) This happened only one time, every time i overcloked again, with Windows 7, and so on ... very predictable.
Now with Windows 8, I didnt do anything yet and the same Problem apperars every time I shut down or restart the PC, me not being able to get the Notebook to get some "sleep" somehow.
I cant tell how this GPU Problem relates to the new Version of Windows, nor can i tell hwo its still existent after i didnt lock the apu anytime after the reinstallement.
any help would be gladly appreciated, though this is a very tough issue.