4-2-09

We had a number of machines that were not showing up on the WSUS console. All machines are pointed to WSUS using an Active Directory (AD) Group Policy Object (GPO), so there wasn't any difference there to troubleshoot. Looking at the registry on the client machines, the HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate settings were correct for our WSUS server and the Automatic Updates & BITS services were enabled and running. Running wuauclt.exe /resetauthorization /detectnow from a command prompt didn't fix the problem computers. The c:\Windows\WindowsUpdate.log file showed that the clients were contacting our WSUS server & even doing updates. The WSUS Client Diagnostics Tool (from here: http://technet.microsoft.com/en-us/wsus/bb466192.aspx ) showed no issues connecting to our server.

I found this solution on the internet:

5. Imaged clients with a duplicate client ID will only appear once in the WSUS Admin Console. Each AU client must have a unique id which is created for each individual install. When imaging systems it is recommended always to use SysPrep. The WSUS admin console will only display one client for each unique ID. If you have multiple clients created from one image which are sharing the same ID, only one will appear in the WSUS admin console. All clients will check in and download updates, but only one will appear and display status in the WSUS admin console. In cases where clients are not checking in, and they were created from images without running SysPrep, the following steps will reset the existing duplicative client IDs.

a. Run regedit and go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate
b. Delete the PingID, SUSClientID and the AccountDomainSID values
(on our machines, AccountDomainSID didn't exist, but SUSClientIdValidation did. I deleted PingID, SUSClientID, and SUSClientIDValidation)
c. Stop and start the Wuauserv Service
d. From the command prompt run: wuauclt /resetauthorization /detectnow

or-

From the command line, once you are sure the AU client is properly configured and not disabled, you could run a batch file (which might look something like this sample) and get the same results:

rem Fixes problem with client machines not showing up on the server due to imaging method

reg delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate /v AccountDomainSid /f
reg delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate /v PingID /f
reg delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate /v SusClientId /f
cls
@echo Triggering detection after resetting WSUS client identity
net stop wuauserv
net start wuauserv
wuauclt /resetauthorization /detectnow

source:
http://www.wsuswiki.com/ClientFAQ