I've just re-installed my computer and decided to try something else. Norton was starting to annoy me and is slowly going down hill. My machine started to run slow, scan takes forever and I had to re-start now and again as it came up with errors.
I now use
www.zonealarm.com and
www.nod32.com Nod 32 has come out top of all tests, costs only about £12 and doesn't slow the computer down one bit.