Try Avira antivirus.Theres a free version that you can download and use,It updates and does not slow your pc down,I agree with you that Norton slows down alot of ppls computers. The New ones you pay 70quid for that take over your whole pc and everything on them and then you need a program that removes them,and even then they have damaged certain files.So don't bother with Norton or McAffi etc, You need a darm good top of the range pc to manage to run them ones and not slow you down! Some of the free ones detect stuff that even Norton don't detect! Iv ad free virus programs get rid of viruses that Norton could not find!