Self-Checking the Microsoft Update Agent Self-Update Log
Sometimes when I get bored, REAL BORED, I go diving into log files and see if there's something exciting there. Usually not. But sometimes I see something that makes me want to say something about it anyway. This is one of those situations.
The WindowsUpdate.log file under %WINDIR% (e.g. C:\WINDOWS) contains the play-by-play events of your Microsoft/Windows Update agent processing chores. Every time it fires up and checks for needed updates, it logs every painfully dull step along the way. But something a little more interesting is looking for where the WUAUCLT agent checks to see if it needs to update itself. This is known as "self-update".
Here's a snippet from a client log to show a section of the log that walks through the self-update verification.
2008-07-14 18:33:03:862 1164 179c Setup Checking for agent SelfUpdate
2008-07-14 18:33:03:863 1164 179c Setup Client version: Core: 7.1.6001.65 Aux: 7.1.6001.65
2008-07-14 18:33:03:863 1164 179c Misc Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab:
2008-07-14 18:33:03:886 1164 179c Misc Microsoft signed: Yes
2008-07-14 18:33:15:209 1164 179c Misc Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wuident.cab:
2008-07-14 18:33:15:225 1164 179c Misc Microsoft signed: Yes
2008-07-14 18:33:15:229 1164 179c Misc Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wsus3setup.cab:
2008-07-14 18:33:15:243 1164 179c Misc Microsoft signed: Yes
2008-07-14 18:33:15:248 1164 179c Misc Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\wsus3setup.cab:
2008-07-14 18:33:15:264 1164 179c Misc Microsoft signed: Yes
2008-07-14 18:33:15:293 1164 179c Setup Determining whether a new setup handler needs to be downloaded
2008-07-14 18:33:15:294 1164 179c Misc Validating signature for C:\Windows\SoftwareDistribution\SelfUpdate\Handler\WuSetupV.exe:
2008-07-14 18:33:15:334 1164 179c Misc Microsoft signed: Yes
2008-07-14 18:33:15:335 1164 179c Setup SelfUpdate handler update NOT required: Current version: 7.1.6001.65, required version: 7.1.6001.65
2008-07-14 18:33:15:335 1164 179c Setup Evaluating applicability of setup package "WUClient-SelfUpdate-ActiveX~31bf3856ad364e35~x86~~7.1.6001.65"
2008-07-14 18:33:15:569 1164 179c Setup Setup package "WUClient-SelfUpdate-ActiveX~31bf3856ad364e35~x86~~7.1.6001.65" is already installed.
2008-07-14 18:33:15:570 1164 179c Setup Evaluating applicability of setup package "WUClient-SelfUpdate-Aux-TopLevel~31bf3856ad364e35~x86~~7.1.6001.65"
2008-07-14 18:33:15:619 1164 179c Setup Setup package "WUClient-SelfUpdate-Aux-TopLevel~31bf3856ad364e35~x86~~7.1.6001.65" is already installed.
2008-07-14 18:33:15:620 1164 179c Setup Evaluating applicability of setup package "WUClient-SelfUpdate-Core-TopLevel~31bf3856ad364e35~x86~~7.1.6001.65"
2008-07-14 18:33:15:691 1164 179c Setup Setup package "WUClient-SelfUpdate-Core-TopLevel~31bf3856ad364e35~x86~~7.1.6001.65" is already installed.
2008-07-14 18:33:15:691 1164 179c Setup SelfUpdate check completed. SelfUpdate is NOT required.
In this rather unexciting example, you can see that this client was already using the most recent version available, so it did not request a self-update. One place where this might be useful is when diagnosing clients which are showing problems reporting up to WSUS or System Center Configuration Manager and you suspect it might not have the latest client agent version.