If you did the registry changes & still couldn't get it to work try the uninstall/reinstall after carefully following their instructions.
"If you continue to receive the error, then go on to the section "Uninstall NAV, clean boot the computer and then reinstall NAV."
Uninstall NAV, clean boot the computer and then reinstall NAV For instructions on how to remove NAV, clean boot (or close all running programs) and then reinstall NAV, read the document How to completely remove Norton AntiVirus 2004 and then reinstall the program"
Good luck - you'll need it! Have had my share of uninstalling/reinstalling Norton products & it aint pleasant. G