You can turn full screen mode on and off using the F11 function key. Or if you slide your mouse pointer all the way to the top of the screen and right-click, a small context menu should let you escape and return to normal. If neither works, try pressing Ctrl+n for a new window.

Does that help?

Occasionally, even if you are not in full screen mode, the toolbars become hidden. To turn toolbars on and off, you can try one of these:

• right-click a blank area of the tab bar
• tap the Alt key > View menu > Toolbars

Occasionally the file that stores your toolbar customizations and window position information becomes corrupted. You can reset your toolbars and window positions back to their defaults by renaming or deleting a settings file. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using

Help > Troubleshooting Information > "Show Folder" button

Switch back to Firefox and Exit

Pause while Firefox finishes its cleanup, then rename localstore.rdf to something like localstore.old

Restart Firefox.

Hope this helps.