You can download the French version from http://www.mozilla.com/en-US/firefox/all.html Once you have installed the French version, you should check a hidden preference: # Type '''about:config''' into the location bar and press enter # Accept the warning message that appears, you will be taken to a list of preferences # Locate the preference '''general.useragent.locale''', if it is not set to '''fr''', double-click on it and change its value to '''fr'''

Thanks, it works!