With some regularity, a co-worker or friend will ask me to fix a PC. Almost always, NAV is installed. The first thing I do is remove it. The users are astonised at the performance boost. I tell them about removing NAV, and strongly urge them to avoid ALL anti-virus programs, since they are all useless. A little instruction on safe use and floppies is enough protection. I usually point out that Windows is the real culprit, and that virus attacks against Linux are virtually impossible.
NAV is surely the worst of a bad lot. What a despicable program.