Many internet providers offer a top quality antivirus package for no charge. You might want to check.

Otherwise, here are current independent, unbiased ratings from a respected source, PCMag, based on results of extensive performance tests done by experts.

Free Antivirus products

Not free antivirus products

I use McAfee provided by Spectrum and Webroot provided by Ally Bank.

As Elmer says, check with ISP or financial services before buying or using free software.

I use Bitdefender and Malwarebytes

Avast ani-virus and CCleaner for daily cleaning, both recommended on Wisconsin Public Radio by Peter Green of Infostar (he's an independent computer consultant).

I use Avast, since the last program update (which it did automatically), it's using a lot more CPU than it used to, I think this is due to a change in the manner in which it delivers a/v updates (streaming as opposed to 'packages' delivered periodically). I'm seriously thinking about changing but not sure which to go with.

My daughter uses Avast and is satisfied with it. I have used purchased copies of Norton over the past several years and that worked well for me. I have an older XP computer that still works well and I kept it when I upgraded to Win 10, but it is no longer supported by Microsoft, however, Norton will install in it, but Norton will not guarantee complete protection since Microsoft has dropped support. (Microsoft no longer writes fixes should someone finds a way in past present virus checkers.)