When I used NAV 5.0, it was possible to get a year free of virus updates anytime by uninstalling/reinstalling. Along came NAV 7.0 (2001), and one could get a year of
free virus definitions only if the uninstallation/reinstallation took place before the end
of the one year updates that Symantec gave with the product. I haven't tried to
get free virus definition updates with NAV 2003 and won't buy NAV 2004.