Marty:
My wife is running a Windows PC (I run a Mac) and we had a very bad incident with McAfee a year or so back - they sent out an update that trashed LOTS of their clients - no internet or email access whatsoever. About a week later they sent out an email to clients telling us to go to a specific website to get a fix to their screw-up. By that time I had already spent $600 to get my system recovered, removed all of the McAfee stuff and never looked back. Since then I've educated myself on what's going on and do my own maintenance, but do it without McAfee or Norton.
I would HIGHLY recommend getting rid of McAfee and installing the antiviral and spyware suites from either Trend Micro or AVG. Either one does a great job (Trend recently helped me defeat the WIN32.ZAFI.B worm that's been making the rounds lately, and AVG is highly recommended by Chris' sysadmin friends) and then set them up to scan daily for a while.
Norton and McAfee both keep malware lookup tables forever and their updates keep adding to the lookup tables so, after a while, they spend a LOT of time looking things up and slow down system performance a lot. Their lookup methods leave a lot to be desired.
gn