In my case, this debugging information proved critical.A Microsoft technician responded to my plea for help well within their 24 hour goal.
It turns out that Windows Update has 2.5 activity log files.
In addition to the "update history", there are two plain text log files in the C:\WINDOWS folder.
Event ID: 672 Description: An authentication service (AS) ticket was successfully issued and validated.
Event ID: 673 A ticket granting service (TGS) ticket was granted.
Event ID: 676 Authentication ticket request failed.