After a long telephone conversation with the eternal support, this has then turned on my computer.
Look here, look there. Try again to start the installation. Actually, everything fits. Again, the error message. The staff then told me it is a known bug that the installation is not sometimes possible since the package pinches with some system files. What these are is boundless out. But on the issue being worked on.
So was advised me to make my computer floored and completely reinstall. I had as yet not really have time and desire.
Class, the Microsoft delivers faulty software!