I've had this discussion on the other board and of the three MSE seems to use up the least resources normally. Norton's and McAfee both of which I have previously used tended to drag my system down. Any of them will slow a system down when running a scan. Computers can only perform one instruction at a time. The question is of personal preference. Do you really feel safer with McAfee? If so then keep paying for it. I rarely stray on the internet so MSE works fine for me. I don't see any added advantage of paying for an AV program when I only go to sites I trust.