Thanks for all the recommendations.
I downloaded & installed MalwareBytes. It found “PUP.FunMoods” and removed it.
Problems remained.
Ran SpyBot. It found & removed “Win32.downloader.bltu”
Problems remained.
Finally discovered that the popups were from “Text-Enhance.com”. I’m not sure where I got it from. They had a go-away link on their website. I clicked it.
It went away....I think. :-) I will rerun SpyBot and MalwareBytes just to be sure.