I've been running Norton Internet Security for the past year and it's been pretty good in terms of dealing with viruses (as far as I know) the only thing is I think it's slowing the computer down. Is this the case with just Norton or most Anti Virus programmes. I'm about to format my pc and my subscription with Norton runs out in about a week? Do you think it would be best to renew or go for a different anti-virus and if different could you reccomend one please?!