Does it work if you open the about:downloads page in a tab? Use Toolbar Layout (Customize) to open the Customize window and set which toolbar items to display. *if missing items are in the toolbar 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 toolbar palette then click the "Restore Default Set" button to restore the default toolbar setup *https://support.mozilla.org/kb/How+to+customize+the+toolbar *https://support.mozilla.org/kb/Back+and+forward+or+other+toolbar+items+are+missing You can check for problems caused by a corrupted localstore.rdf file if the above didn't help. *http://kb.mozillazine.org/Corrupt_localstore.rdf