My point is you can have a virus and not even know it. There are many types of viruses, and not all show themselves right away and are destructive enough to cause a major problem. I had a few viruses that Norton caught and when I read up on them I found they use your system to send out information to others. I don’t know about you, but I don’t need any Internet slow-downs just because someone is borrowing my PC and using some of my bandwidth. Other viruses don’t show themselves right away: some trigger on certain dates, some when you open an application, and some slowly work away messing your PC up a little at a time until it’s so messed up you have to do major work to repair things. My wife had a Chernobyl virus that was on her PC before she had anti-virus. It activated on the 26th of the month, when the Chernobyl accident occurred, and it slowly messed stuff up. It finally got to the point where she couldn’t do anything. I had to format to get rid of it.