BTW first thanks for your help.
I run aswclean for version 5,6,7, and 8
I even tried to install AVG but pc didn’t even start. The it isn’t an AVAST related problem.
Then - yesterday evening - I installed Microsoft Essentials - not my favorite AV - but then it worked. No problem at all.
Today a removed several other malware / spyware programs but no result.
BTW using aswclean what directory/map do I have to enter in the secend bar (under the version). Because I cannot find a map that points to AVAST. Can I leave it blank?