When you take a computer in for repair, you are paying for expertise (and rent, insurance, payroll), not just the fix. I have been using the paid version of MWB since it cost $10 for a lifetime license. The paid version is real time so it can catch stuff immediately. Defender in a great anti-virus (certainly as good as the overpriced and huge overhead Norton and McAfee) but much of the crap you can pick up on the Internet are not technically viruses, but malware, something MWB is especially good at. The paid version is up to about $40 @ years, but they have offers and sales that are usually half that (if you select auto renewal you are not offered discounts, something to consider). The point being is if your computer was "loaded", you would probably benefit from added security.