I should note that I use the paid version of Malwarebytes on all my computers. You may still be able to get a lifetime key but they are moving to a yearly subscription fee soon. I paid $15 for each of my lifetime keys and it's really worth every penny. They are so good and in demand they are moving to a $25 a year subscription.
Avira is very good. I use Avira on my desktop and Avast on my laptop and both are excellent. I would recommend either. Both score very well in independent testing. AVG is also very good.
I should note that I use the paid version of Malwarebytes on all my computers. You may still be able to get a lifetime key but they are moving to a yearly subscription fee soon. I paid $15 for each of my lifetime keys and it's really worth every penny. They are so good and in demand they are moving to a $25 a year subscription.