I only use Windows in a VM now, but for years I ran Windows with no AV outside of whatever Windows set up on it's own. I only got two viruses in my life, and both times I was asking for it (downloading sketchy looking things off of Kazaa when that was a thing).
Vipre has a nice offline scanner you can download. They used to update it daily, but I haven't used it in awhile since I mostly manage Linux now. https://www.vipreantivirus.com/vipre-rescue-virus-removal-to...
Sometimes you do: https://www.symantec.com/connect/blogs/malvertising-campaign...
Run an adblocker and up to date Windows 10.
For anyone doing tech support over the Easter long weekend: https://decentsecurity.com/#/holiday-tasks/
I have to barge in here and mention that doing totally reasonable things can result in getting malware installed on your systems.
The most glaring case was the early Windows XP era, when it was enough to plug in the Ethernet cable during installation to get malware. I had to download the service pack and install it offline before plugging in the network.
Today, I'd point out that ad networks' code is barely scrutinized, and they can hit unpatched vulnerabilities all right (sorry for not providing examples).
That's why it's so important to discuss & combat conceptually, not specifically.