I thank you for your information, and will have a look at your little guide in the afternoon.

Here all computers run on Windows - at home as well as at school or at work. I do not want to have different OS, and my children either. They don't use the computer very often (Playstation gamers), just for homeworks and so.

I'm a Windows fan, what shall I say more?
I have always had Windows, and when you know, what you do, then your system will run without problems - the main problem with Windows is the user 😉
I think, that my problem was the cheap SSD, which I installed a few months ago. I will know it as soon as I have a running system ;)