I think the problem could be in the non default acented caracther on the path: ä I have already this problem in the past.
Good tip! If it has been the case before, it might as well be what I'm experiencing.

Clip and paste folders/files: no I made sure everything was completely clean. When it comes to Avast! I wouldn’t even have use of some saved data. Some other programs though work this way, but what I usually do then is to simply back-up the folders in question and see if I can integrate them to a new installation.

I try your recommendation and put Avast! into a folder without any special character.

Thanks!

(I’m really happy that my system boots up in about 30 seconds!)