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.''' Now do the same in the computers Programs Folder. '''Windows:''' Start > Control Panel > Uninstall Programs. '''Mac:''' Open the "Applications" folder. '''Linux:''' Check your user manual. ------------------ After the problem is fixed, Bookmark and use this; Download the '''[https://addons.mozilla.org/en-US/firefox/addon/searchreset/ Mozilla Search Reset]''' {web link} This add-on is very simple: on installation, it backs up and then resets your search preferences and home page to their default values, and then uninstalls itself. This affects the search bar, URL bar searches, and the home page.