I have recently been recommended to ditch Norton and use AVAST. It's free, regular updates and does atttempt to fix the damaged files where Norton invariably says it cannot.
I also use AdAware as an Adware/Spyware prevention. Works well, cheap (£30?) and has rescused many friends PCs from "death by adware". It removed over 2000 adware objects from a neighbours PC, it was taking half an hour just to boot it.