Move your mouse to the top of the Firefox window, then right click. You will see a menu of the available toolbars.

See also:

• http://kb.mozillazine.org/Prevent_websites_from_disabling_new_window_features

Make sure that all toolbars are visible and that the search bar is still positioned on a toolbar.

• Firefox menu button > Customize > Show/Hide Toolbars
• View > Toolbars (press F10 to show the Menu bar)
• Right-click empty toolbar area

Use Customize in the "3-bar" Firefox menu button drop-down to open the Customize window and set which toolbar items to display.

• if missing items are in the Customize palette then drag them back from the Customize window on the toolbar
• if you do not see an item on a toolbar and in the Customize palette then click the "Restore Defaults" button to restore the default toolbar setup

You can check for problems caused by a corrupted localstore.rdf file if this didn't help.

• http://kb.mozillazine.org/Corrupt_localstore.rdf
• http://kb.mozillazine.org/Preferences_not_saved

In Firefox, I clicked on the (upper-right) 3-bar menu button > Customize Button (lower left - in box). "Additional Tools and Features" appears within the window. The FF Search Bar "Icon" (drop down w/ engines) was in the list, I clicked and dragged it into my address bar. This did the trick - hope it works for you. (Aug 19, '14)

I'm a newbie to the help forum; so many others helped me here I thought I'd take a shot at this solution. Good luck.