Press "Alt" to show the toolbars, then click on View > Toolbars > Navigation bar (turn on the checkmark there). If the navigation bar was already checkmarked then you were probably in full screen (F11), or you removed the location bar from the Navigation tool bar. Press F11 to see if you drop out of full screen mode. Full screen is where you window takes up the entire screen without toolbars showing. (at least not with Firefox as delivered without extensions). If you have the navigation bar, but are missing the location bar then use "Alt" > View > Toolsbar > Customize and drag the "Location bar" back to the Navigation bar. If you are not familiar with changes made to Firefox 4 and 5, you would not be first to think the Navigation is missing when it is actually showing. Tabs bars was put above the Navigation bar and the home page button, back/forward arrows were moved to the right of navigation bar. You can make '''Firefox 5.0''' look like Firefox 3.6.19, see numbered items 1-10 in the following topic [http://dmcritchie.mvps.org/firefox/firefox-problems.htm#fx4interface Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 5.0, or 4.0.1, look like 3.6)]. ''Whether or not you make changes, you should be aware of what has changed and what you have to do to use changed or missing features.'' * http://dmcritchie.mvps.org/firefox/firefox-problems.htm#fx4interface

How do I Customize the Toolbars? * https://support.mozilla.com/en-US/kb/how-do-i-customize-toolbars Common Questions after Updating Firefox * https://support.mozilla.com/en-US/kb/common-questions-after-updating-firefox Check and tell if its working.