Can you please try to explain the problem with a bit more detail?

Normally, when you open Firefox, you will see an address bar at the top. You just have to enter www.facebook.com there, then press Enter, and Facebook should open up. You will also have to log in to Facebook with your user name and password to actually be able to do something there.

Can you attach a screenshot that shows the problem?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

Use a compressed image type like PNG or JPG to save the screenshot.

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.
You can click the Maximize button at the top right to leave full screen mode or right click empty space on a toolbar and use "Exit Full Screen Mode" or press F11.

• https://support.mozilla.org/kb/how-to-use-full-screen

You can check for problems with the localstore.rdf file.

• http://kb.mozillazine.org/Corrupt_localstore.rdf
• https://support.mozilla.org/kb/Toolbar+keeps+resetting