Are you talking about the home page, right? Try restore you home page to default: *[https://support.mozilla.org/en-US/kb/How%20to%20set%20the%20home%20page How to set the home page] Also you can go to '''about:config''' search for '''browser.startup.homepage''' change its value to '''about:home''' (default home page). *[http://kb.mozillazine.org/About:config about:config] Also: *[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode Firefox in safe mode] *[https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware Problems caused by malwares] *[https://addons.mozilla.org/pt-BR/firefox/addon/searchreset/ Reset Search]

Download and install an official version of Firefox. <br /> http://www.mozilla.com/en-US/firefox/all.html

You can install the Firefox release from the Mozilla server. Download and save the full Firefox installer to the desktop and start the installation with a double-click on the desktop icon. You can find the full version of the current Firefox 27.0.1 release in all languages and for all Operating Systems here: *http://www.mozilla.org/en-US/firefox/all.html