I have tried absolutely everything I can find online, including http://support.microsoft.com/kb/83694
, to solve my problem. I am receiving Error number: 0x80072EFD when trying to update my Windows Server 2003 machine. Windows Defender also cannot pull in any updates.
The machine is a backup Exchange 2003 server. I have disabled Norton Antivirus file protection, run a full scan with updated Norton antivirus defs, run Malwarebytes, manually updated Windows Defender defs and ran a full scan, and nothing seems to help. Windows firewall is also turned off.