Reinstalling Vista definitely sounds like overkill and unnecessary, since it is still working.

You could try scrubbing out all traces of BearMesh 6 and reinstalling it, though I would advise
against letting that RIAA-friendly company spy on your downloading habits anymore. You can
certainly get more mileage out of Myspace and IRC than the profile and chat in that software.

Either option will probably render most of the DRMed music you downloaded with BearMesh unplayable.