If I have a PC, what is the best anti-virus software I can get online?

[Denzil_DC]

10. I also use the Kaspersky three-license version

along with the free version of Malwarebytes for occasional use as insurance. Kaspersky's yearly subscription is good value, IMO.

As borne out by the chart in the factsheet linked above - https://www.av-comparatives.org/wp-content/uploads/2016/10/avc_factsheet2016_09.pdf - we've found it very effective, and (touch wood) I can't recall the last time it let anything through, having switched to it for past four or five years. Prior to that, my partner was getting infections just by clicking on news/politics sites that were a bit off the beaten track, and I appreciate not having to waste time cleaning up after them, along with the worry that something else might have gone undetected. (OTOH, I did learn a lot about malware-busting, which has helped when friends' systems have been compromised!)

Kaspersky can occasionally be a bit resource-hoggy and slows down startup on our older systems, though all this seems to have improved with newer versions. A bit of tinkering with the settings (e.g. I've disabled System Watcher as it was causing too many problems) doesn't go amiss. It's worth it for the peace of mind, and avoidance of waste of time we experienced in the past.