F10 toggles the menu bar off or on but if you've upgraded to FF29, this no longer includes the orange button. To permanently get your menu bar ON, right-click an empty space to the right of your tabs and select from the drop-down list instead of using F10.

Make sure that you do not run Firefox in full screen mode (press F11 or Fn + F11 to toggle; Mac: Command+Shift+F). *https://support.mozilla.org/kb/how-to-use-full-screen If you are in full screen mode then hover the mouse to the top of the screen to make the Navigation Toolbar and Tab bar appear.<br>Click the Maximize button (top right corner of the Navigation Toolbar) to leave full screen mode or right-click empty space on a toolbar and choose "Exit Full Screen Mode" or press the F11 key. ---- Firefox 29 and later versions have the Australis interface that looks different than the user interface in Firefox 28 and older versions. *With the Australis interface the orange Firefox menu button has been replaced by the three bar Menu button at the far right end of the Navigation Toolbar<br>A consequence of this new menu button is that you no longer can hide the Navigation Toolbar *There is a star like button to the right end of the search bar on the Navigation Toolbar to bookmark the current web page and a "Show your bookmarks" button next to it to open the Bookmarks in a drop down menu *It is still possible to have the menu bar visible via the right-click context menu on the toolbars to have menus like the the Bookmarks menu See also: *https://support.mozilla.org/kb/common-questions-after-updating-to-new-firefox *https://support.mozilla.org/kb/learn-more-about-the-design-of-new-firefox *https://support.mozilla.org/kb/how-to-make-new-firefox-look-like-old-firefox