Few put two and  some people know, not to run two antiviruses software at a time. I thought two scan at time will save my time. I got Norton free from Comcast, MacAfee was the worst.Something is better than nothing.

You are right: when I had only 2 gb ram sometimes it used 80% resources as you said. Now it is 6 gb, do not feel much different.

I got exact 6 intrude on other laptop too: Thank you.