McAfee and Nortons are both POS, overpriced and creates problems. We tried both (one of my family actually worked for McAfee and couldn't keep it running). Finally blew them all off and put on AVGFree. Haven't had a virus one since then. It was amazing how many viruses McAfee and Nortons had let through the first time I ran AVGFree.
BTW, if you're having freeze up problems, etc there's a very good chance it's Nortons.
Folks & family have troubles they'd like me to fix and are perplexed that I don't know how.
I have never had these problems and therefore don't know how to fix 'em.