Huh. In theory, there shouldn't have been much likelihood there for an infection. And yet there (unless I'm being confused by something in the German language report) is a Potentially Unwanted Program, or "PUP."
Ordinarily, given all this, I'd probably have just told you to let Malwarebytes take care of it, and sent you on your way to sevenforums to try to straighten out the Windows issues. However because we are pretty much at the end of the things we could try to resolve it--treating it as just a Windows or Norton issue--I think I'm going to suggest you go to one particular removalist forum (info copied from delphinium's list on our Tech Outpost):
Bleeping Computer:
Always very good. They run scans to check the system first before any removals, they use the latest tools, and if they run into trouble, they have the ability to fix Windows problems as well. They have higher level specialists to handle the higher level infections. They will ask you to remove illegal software and u-torrent.
Because they are so well known, it can be a lengthy wait to get assistance.
http://www.bleepingcomputer.com/forums/f/22/virus-trojan-spyware-and-malware-removal-logs/
As delphinium notes, they'll be up to the task of the worst malware you might have...but they'll also be happy to straighten it out for you if it's "just" a PUP and a Windows 7 issue.
V/R,
--DistEd2
[Edit: I can't quite reconcile what appears to be a PUP detection with what appear to be "0" threats detected in each Malwarebytes category--so I may be misunderstanding the translation somewhere. But given the uncertainty, plus the fact that there's definitely a tricky Windows problem involved, I'd rather err on the side of caution--unless someone else comes along with a fresh perspective and some better ideas.]