If you have the Firefox user interface (menu bar) in the wrong language or want to change the current language then you can get Firefox in the language of your choice here: http://www.mozilla.com/firefox/all.html Uninstall the current Firefox version, but make sure that you do not remove your personal data. Install the new Firefox version of the wanted language. You may need to (re)set the pref "general.useragent.locale" to the preferred language (e.g. "en-US" or "en-GB") on the about:config page. You can open the about:config page via the location bar, like you open a web site. Use the Filter bar at the top of that page to quickly locate the pref. See also http://kb.mozillazine.org/Profile_backup and [[Backing up your information]] ---- There are other things that need attention. Your above posted system details show outdated plugin(s) with known security and stability risks that you should update. # Shockwave Flash 10.1 r85 # Next Generation Java Plug-in 1.6.0_17 for Mozilla browsers Update the [[Managing the Flash plugin|Flash]] plugin to the latest version. *http://www.adobe.com/software/flash/about/ Update the [[Java]] plugin to the latest version. *http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)