I never used Avast. Having been hacked I found it was installed on my system by the people who "fixed" my computer. Grrrr. It was not very friendly and did not play nicely with my other programs. I had to get rid of it. (Meaning my brother did ).

Are you able to take it to a decent computer place and ask them to do what you need? They may be pricey but they will be able to fix it in a quarter of the time and frustration that you find yourself in.

If you ask around the friends who have computers maybe you can find a decent computer company where you live.