Nonsense. No one needs anti-virus/spyware software running all of the time checking every single file what gets accessed, this singly is the cause of many peoples "my machine takes a while starting up" and lets not even mention the amount of un-needed program running at start up.
I agree. I don't use anti-virus and don't have any problems. I don't know why so many people insist on running security software which slows down the computer.