What can i do to regain the function of the close browser button?

Question

after using firefox for a number of weeks without problems, today the close browser button is not functioning! (white cross on red ground) The only way to close the browser is by using the task manager end task. This is a simple problem but what can I do to fix it? I have tried updating but not reinstalling.I dont have any more details I am afraid, the button just doesnt work. I dont think it is a problem with my computer cos for example 'word' closes as expected. Likewise Internet Ezplorer. More than that I do not have any idea why this is happening.

Answer 1

That is Close the Window button, not close the browser, and with Firefox that makes a difference because of subtasks.
The following may not completely eliminate having to terminate Firefox through the Windows Task Manager but it will come very close.
'''Plug-in and tasks started by Firefox may continue after attempting
to close Firefox''' The "X" in the upper right-hand corner closes the
Window (same as Ctrl+Shift+W) but even if it is the last Firefox window,
it does not necessarily close Firefox .
The only '''proper way to exit Firefox''' is to use '''Exit''' through the
File menu, not the "X" in the upper right corner of last Firefox window.
In the 4.0 and up with the "Firefox" button that would be Alt+F then X
* '''Firefox hangs''' | Troubleshooting | Firefox Support <br>http://support.mozilla.com/en-US/kb/Firefox%20hangs#w_hang-at-exit
Use the '''Windows Task Manager''' to remove all running firefox.exe in the "'''Processes'''" tab of the Windows Task Manager, then restart Firefox.
''very infrequent --'' If Firefox will still not start, remove the parent.lock file from the profile which is created each time Firefox is started to prevent other Firefox tasks from running, see<br>
http://kb.mozillazine.org/Profile_in_use#Remove_the_profile_lock_file
'''Avoiding Problems with close/restart''' ''choose either extension''
:Use to close and restart Firefox after enabling or disabling an extension, switching to a new theme, or modifying configuration files, then you don't have to worry about delay or have to look in the Task Manager to see if Firefox is closed yet.
*"'''Restartless Restart'''" extension for Firefox 4.0+ only (2 KB download ) --
uses keyboard shortcut "'''Ctrl+Alt+R'''" or a file menu option.
<br>https://addons.mozilla.org/firefox/addon/249342/
*"'''QuickRestart'''" extension (34 KB download) ''(older extension for those below 4.0)''<br>
uses keyboard shortcut "'''Ctrl+Alt+R'''" or a file menu option. <br>https://addons.mozilla.org/firefox/addon/3559/