Now something new. The blue "a" icon on my windows xp taskbar, in the lower right corner, near the clock has a red and white marks on it, evidently telling me that it is not functioning.
As I said earlier, I can update manually.
This development of not being able to upgrade automatically occurred immediately or soon after the my registration number was renewed.
I deleted (or deactivated) McAfee in favor of AOL firewall, but it did not help the Avast delemna.