OK
I removed S&D with REvo Uninstaller
I run ASWCLEAR in safe mode, I choosed nr 1 in the list Avast! 4 HOME Pro

Rebooted to Normal mode
Run avast_free_antivirus.exe

So far so good
I got a green smiley saying all installed
And then suddenly a BS saying
No_more_irp_stack_locations

Restart only possible in safe mode