That's regrettable. In that event, I'll reiterate my previous suggestion of consulting Symantec, the producers of Norton security products. If you would prefer German support from them, you can reach that site here:
http://www.symantec.com/de/de/index.jsp
Chances are, as I've mentioned before, the alert is a "false-positive", meaning of course that Norton has incorrectly identified the setup file as potentially malicious. Most current versions of anti-malware software employ heuristics that "guess" at a file's potential harmfulness to a system based on behavior of known malware/viruses. This is provided as additional security to help avoid infection by newer, as-yet-to-be-officially-identified malware.
The usual 'fix' in these cases is to go into Norton's configuration and add an exception or exclusion rule that would inform Norton to ignore the respective file altogether. When the file in question is an install or setup file, one sometimes may have to enter additional exception rules for the program once installed, though this is rare.
While I would be more than happy to assist with how to do this, I feel it would be a much better idea to consult Symantec/Norton directly as this would give them the chance to test the file directly, and if found safe, give them the opportunity to include an exception in future malware/virus/signature database updates so that their software does not incorrectly identify it in the future. As well, in the off-chance that somehow your copy of the setup file is indeed infected, then Symantec can better assist you in protecting yourself from it.
One last thought here: you are the fourth person I've seen so far to mention this particular issue, so resolving this would definitely help others! Should you seek further assistance from me or this forum, please let us know exactly which Norton product you are using and it's version number. I sure hope this helps!
