I am trying to restore the Most Visited tab which I've had until just now, and it has disappeared. Found someone's "answer" to the problem, which was to type about:config into address bar which i did, then to find "browser.newtabpage.enabled", right click on it and hit RESET. Problem is, of the various options only "reset" was not highlighted/active so couldn't Reset.  ??? Anyone got any suggestions please, I'm tearing my hair out.