Enabling extended logging for Windows Update Agent Service

The Windows Update Agent Service ( wuauserv ) is responsible for keeping the system updated by scanning the system for missing updates and installing those if properly configured to do so..

WSUS and the Windows Update Site uses this client agent to accomplish tasks.. If you are aware of MBSA, which is a Microsoft Tool to asses your system security compliance level, also uses the windows update agent for scanning. Additionally if you have any custom application which uses windows update APIs to perform scan / installation of updates also uses the same service..

Pretty critical eh.. It leaves behind a log file.. which is very difficult to decrypt for fresh eyes.. Even then some times the logged information proves insufficient to identifiy some issues..That is when you should be considering the extended logging option of Windows Update Agent.

How to do that ?

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Trace
Value name: Flags
Value type: REG_DWORD
Value data: 00000007

Value name: Level
Value type: REG_DWORD
Value data: 00000004

This registry key turns on an extended tracing to the %systemroot%\Windowsupdate.log file. Additionally, this registry key turns on an extended tracing to any attached debuggers.

Refer to the MS Documentation for additional details. http://support.microsoft.com/kb/902093

P.S. : While investigating a very peculiar MBSA Scan issue ( offline scan wouldn't work if network cable is disconnected.. Then why shoud it be called an offline scan right ? ). Once the extended scanning was enabled, it gave some references to the ipV6 interface not being up and stuff..

In windows xp, the ipV6 stack can be installed or removed easily by

c:\>ipv6 install

and

C:\> ipv6 uninstall

The system that gave issue did not have the ipv6 stack enabled. Taking clues from the log file, I enabled it and scan started working. .Not happy yet as I am yet to reach to the root cause.