After a search, I wasn’t able to find an exact answer to this question, which is: I have a terribly slow (rural) dial up speed of 26K. If I install
antivirus programs, pages load even slower. Some, not at all.
Is Avast capable of doing some cleaning offline? How do I set it up for that?
Happy Thanksgiving and thanks to all those who answer.
Alan 
I too have dial-up and although it is much better than yours at 49-50KB connection speed, I don’t see any appreciable difference in my page loading.
What Operating System are you using ?
What is your firewall ?
What browser are you using ?
Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?
You could terminate the web shield provider and then avast won’t be scanning the web http content, that I feel is a decision to be avoided if at all possible as it can intercept malware before it has a chance to get on your system. The Standard Shield should depending on the file type, your settings (and browser) scan newly created files as they arrive in the browser cache, so you wouldn’t be totally unprotected.