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.

The other day, three users posted a similar problem. Two of them had such a bad infection that they couldn't even open the Add-ons page properly until they switched to Firefox's Safe Mode. In case you need the steps for that:

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Then your add-ons shouldn't be able to interfere with managing add-ons.

Thanks for the responses. Your suggestions did not work.

Hi maryanne.dugan, which symptoms do you have:

(A) Startup or "home" page changed to Yahoo -- see: How to set the home page

(B) Default search engine changed to Yahoo -- when you type in the address bar, instead of saying "Search with Google" the top line of the drop-down mentions a different search engine -- see: Change your default search settings in Firefox

(C) Searches are hijacked -- when you type in the address bar, it says "Search with Google" but the results are served on a different site -- please copy/paste the address of the results page into your next reply to see whether it provides more information

Note: including a URL in your reply may delay its appearance due to link moderation.