Question : WSUS - Clients check in and dissappear, replaced by another client

Hi all,

I have scoured the postings here but not come up with a solution so figured I would ask first.  

I have a brand new WSUS 3.2 installation running on 2008 R2 EE with a local SQL 2k5SP2 db install.  I have configured the GPOs for all requisite domains to report into the WSUS server for patches.  At this time i have only 26 clients checked in (out of a couple hundred) and have been stumped as to why they are not checking in.  One smoking gun i found while i was troubleshooting was that when I logged into a client (we will call it .160) i knew had not checked in and ran  a gpupdate /force, validated the policy applied, net stop/start on automatic updates and then a wuauclt /detectnow.  Nothing.  So i ran the wusauclt /resetauthorization and boom, there it is in my console.  However, now I am missing a machine in the console (.161 which i know was there).  I have been able to duplicate this several times with several different machines.  I confirmed that the SIDs are different, as are the MACs, IPs, etc.  Any thoughts?

Thanks for your help.

Answer : WSUS - Clients check in and dissappear, replaced by another client

Here's a script that will do it for you. You can run it as a startup script, until you're sure all clients have run it.
Net stop wuauserv
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
Net Start wuauserv
wuauclt /resetauthorization /detectnow
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