Microsoft Essentials is free (was)..I have it on this WIN7 that I'm using right now. I think that's what I have on my WIN10 also.
AVG has a free one that I use... You can check into it. I have been using it for years.
I think you can still get a free version when you renew. I have it.
Just type in Avast free and the page will come up.
I thought Avast was free. Did they change their policy?