Please note: These instructions should also be followed if changing from one Norton product to another. ie a paid/trial subscription from Norton to the Comcast version, or a version upgrade of NSS which is more than one upgrade old.
Once installation is complete, open NSS and manually Run LiveUpdate (located on drop-down under PC Security on left side of main page of NSS) as many times as necessary for it to respond "no more updates available". If a reboot is requested, reboot and then continue to Run LiveUpdate until it responds "no more updates available" and then reboot one last time. Your installation should now be up to date definition wise and ready for use.