You may find this helpful:

Google Redirects Me to Some Other Search Engine - Help!

and especially this:

Suspicious results and strange behavior: Strange pop-ups and other malware

Thank you, but I was hoping for something written in English. I am rightly considered an advanced computer user, but I'm not a programmer and don't speak programmer-gibberish. I apparently have malware or a virus that AVG can't find. How do I find it and delete it?

One step you might try, is to look at your add-ins and extensions, and see if there is something odd there. I was experiencing similar behavior, and there was an add-in that once deleted, solved my problem.

Thanks, Joe. But no luck there. My few add-ons are good.