Thanks for your reply.

-Point A.
I applied “Automatic Update”, “Ask…” for program updates.
-Point B.
None is checked, I have just applied the “My computer is permanently connected to the Internet.”
-Point C.
Proxy settings set to manual. I don’t put the proxy information on IE connection settings, because the proxy ( using Squid ) only allows the desktops to connect to *.avast.com
The desktops are not allowed to connect to the internet by any means, hence the manual proxy setup on Avast, allowing the desktops to update virus definitions and program updates from Avast.

At this point, only one change made to the update settings, which is “My computer is permanently connected to the Internet.”
I’m going to monitor my proxy log in a day to see what will happen.
Will report back to this thread.