You have downloading firefox(disk in the box icon)but you don't install it yet, you must double-click to install it. If you have install other firefox version go to HELP and then ABOUT FIREFOX and press CHECK FOR UPDATES to '''updating''' firefox to the latest version. Verify also that your system meets the hardware requirements : https://www.mozilla.org/en-US/firefox/7.0.1/system-requirements/index.html thank you Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.