Microsoft Update works but Windows Update not in Vista

I hope someone can help me get this Windows Update problem in Vista fixed: Error(s) found: Code 80072EFD.

I have tried this Microsoft Help & How-to (Windows Update error 80072efd), and also tried all methods in this Microsoft Knowledge Base article, and neither helped.

The interesting thing is that Microsoft Update works perfectly.

My computer is running Vista 64-bit version and is on a domain, and I am thinking maybe something wrong with the group policy that blocks 64-bit PC’s communication with Windows Update service, or something I don’t know.