please go to firefox > addons > extensions & remove any suspicious entries (toolbars, things that you have not installed intentionally, etc). also go to the windows control panel / programs and remove all toolbars or potentially unwanted software from there and do a full scan of your system with the security software that you have in place and/or a different tool like the [http://www.malwarebytes.org/products/malwarebytes_free free version of malwarebytes]. [[Remove a toolbar that has taken over your Firefox search or home page]]

Some toolbars are installed applications on your computer and must be removed using the Windows Control Panel *See - http://kb.mozillazine.org/Uninstalling_toolbars *See - https://support.mozilla.org/en-US/kb/Cannot%20uninstall%20an%20add-on