Thanks conghoaxa1. Working without any problem. The update contains a new Intel Management Engine. Easiest way to get this running is to update the original file from within the BIOS with M-Flash and choosing the option "Update BIOS and ME" before using the modded file and afudos.
Perhaps it isn't even an issue. This Windows 8 Feature seems to support things like Secure Boot, Fast Boot and other stuff you may want to have in a tablet. This way it can update itself even while turned off and boot in a few seconds. To achieve this, the BIOS won't look for changed hardware, trying to bring down the time until Windows starts. I had to turn it off, because my graphics card doesn't support the GOP - graphics output protocol. Whatever that is. Perhaps SATA will only appear in Windows 8 after startup. Well, I think I can live without. Besides of that, the modded BIOS worked as well as the original. Windows 7 was immediately activated with it, as expected. You can update ME with afudos as well, but you have to use a parameter like /MEUF. I did not test that, just saw it in the options.