Windows Vista Update Error 0x80072EFD

Could not update Vista SP1 due to 0x80072EFD error, so I started out by manually updating to SP2.  No success.  This was driving me absolutely insane until I actually read the C:\windows\windowsupdate.log file.

First, try resetting the HTTP proxy through an elevated command prompt with the following command:

netsh winhttp show proxy

If you are still receiving this error, be sure you follow this KB:

http://support.microsoft.com/kb/836941

If this does not resolve the problem, try resetting Windows Update Components with the following Microsoft Fix It:

 http://support.microsoft.com/kb/971058

If this still does not work, be sure that WSUS GPO & registry settings are NOT in place!

First check GPO:

Administrative Templates->Windows Components->Windows Update, under the setting "Configure automatic updates."  If this is already set to "Not configured," then check registry settings under:

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate

For any WSUS keys.  Deleting the WSUS keys I found in the registry remediated my issue.