Thanks a lot to all.
It is really strange. I tried on my other Laptop (Vista 64)=> no additional SW
The PC with the issue has WIN7 and I did not install SW the same day I installed AVast.
I think it happened by any chance that there is the same installationdate. May be via automatically update??. The "goto SW" could be from a Webinar I visited some days before
So I think everything ok, avast installation ok
tks