"Top/Bottom of current window" and "when download completes" are not standard Windows sounds. Are you certain you didn't have some sort of third party software installed that was doing this?
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore