Sadly, you're exposed as nothing more than a NAV (or anything Symantec)
apologist! You are easily one of a very very few that supports it claim as
the "best". Most of the MVPs here, and more notably, the ones that give the
most knowledgable and accurate help here, all suggest to stay away from NAV.
Even former users of NAV (that also include MVPs) all say NAV uses to many
resources, and wants to remove, or alter files it has no business touching,
hence why many have problems with it.
FWIW, the free AVs that are reliable, are better for the average user, less
costly (obviously), and will find it less intrusive on system usage, and
file handling.