Norton is a bloated pig that hogs resources.
The tool you should have used was Malwarebytes.
Further to protect your computer you should have installed Spybot(free). Run it once a week to make sure everything is clean.
F-prot should stop just about anything and runs in the background without beating on your hard drive the way Norton does.
Seems to me, that the best way to stay out of trouble is to be very careful about checking out new websites.
Used to be pretty common getting viruses from emails, especially those stupid chain emails, but most email hosting these days seems to stop the problems??? Thankfully so, because it is much harder to get folks to stop sending you stupid email stuff...