Seems to be lots of hits on google for the error code and windows update, http://www.google.co.uk/search?q=error+code+80072efd+windows+update.
Another one of them: http://social.technet.microsoft.com/Forums/en-US/itprovistasecurity/thread/6d2bf715-33b2-4cb3-b114-9217ac8e6771/