Firefox changing search from google to yahoo?

There is a version of Firefox optimized for Yahoo! which may have downloaded by default e.g if you already had the Yahoo! toolbar. Try downloading it directly from a href="https://www.mozilla.com/en-US/firefox/new/" rel="nofollow"https://www.mozilla.com/en-US/firefox/ne…/a and install that, it should remove the Yahoo part without damaging your bookmarks etc.