If you use Office 2003 and installed the updates released over the last couple of days and are now experiencing problems, try uninstalling this update: //support2.microsoft.com/kb/908531
Among the symptoms are the inability to open files using the File, Open menu (or save using File, Save) and "Word is unavailable…" error message when it's set as the email editor.
For resolution, see //support2.microsoft.com/kb/918165
Published April 13, 2006. Last reviewed on June 17, 2011.