Hi and thanks for your reply.
Firstly it was a clean OS install (see above) and no Avast remnants possible. Today they might be some though.
Secondly and I swear on everything that is saint to me, I ran that Avast clear tool once and when it was done ALL FILE FROM MY DESKTOP WERE GONE. I will never dare to run that thing again.
Unless someone figures this is an OS related thing I might be stuck out of Avast.
Best regards!
PT