Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; (<Control> [Mac=<Command>] <Shift> A)

In the Add-ons Manager, on the left, select Extensions. Remove “ Yahoo “ Anything.

Also remove SafeSearch, SearchAssist Incognito, FileConverter Addon, SearchLock, DiscreteSearch, WebSearch, Findwide Search Engine, securedsearch

Now do the same in the computer’s Programs Folder.

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the Applications folder. Linux: Check your user manual.

None of the things you suggested were there. I removed Search with your search engine of chance, then did a a search and got bing, so Thanks!

Glad to help. Safe Surfing.