Medical doctors get kickbacks from pharmaceutical companies, maybe this "Computer Doctor" gets a kickback from Norton?
Anyway, to the issue, I've been happy with a combo of MSE and Threatfire (uses heuristics to catch zero-day threats and doesn't conflict with MSE) on my own machines, and Panda Cloud AV and Threatfire for family and friends who probably will never bother to update their definitions database. I also use Malewarebytes for the occasional on-demand scan prior to making a backup image of the system for my peace of mind to know that the image is malware-free.
I once checked out a computer a friend had just gotten back from the repair shop. I found that along with a re-install of Windows they included a dodgy AV with keystroke logger and password sniffer included, just goes to show you can't trust some of these computer repair places.