I cannot find how to access the Firefox toolbar on my Windows 7 desktop. There is no Firefox 'Button' that I see.
Firefox either displays the Firefox Button, which in turn produces a drop down menu, or it displays the older menu toolbar.
On windows pressing or holding the Alt key should temporarily display the menu bar,, even if the Firefox button is displayed.
Also make sure that you do not run Firefox in full screen mode (press F11 or Fn + F11 to toggle; Mac: command+Shift+F).
If you are in full screen mode then hover the mouse to the top to make the Navigation Toolbar and Tab bar appear.
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.