After April 24, 2012, Firefox version 3.6 will no longer be supported. All customers are strongly suggested to update to version 11/12.
Additionally, starting with Firefox version 13 (expected to be released in June 2012), Firefox will no longer be supported on Windows 2000 or Windows XP-SP1 systems.
Please see the follow URL for details and begin taking the appropriate steps to ensure you are able to run the most current versions.
http://blog.mozilla.com/futurereleases/2012/03/23/upcoming-firefox-support-changes/