How to re-enable removed computer in WSUS

[hatred]

I want to do some testing with WSUS and have tried to delete a computer from WSUS. It used to work fine but I want to re-add it to WSUS as well. So, I have tried restarting, changing the computer name and restarting, deleting the three registry keys in HKLM\Software\Microsoft\Windows\Currentversion\Windowsupdate and also running wuauclt /resetauthorization followed by a restart and then run wuauclt /detectnow but nothing seems to be working for me. If I am checking the windowsupdate.log then I see that the client report "WARNING: Failed to obtain SusClientId". Does anyone have any clue for this issue? Thanks.

[The Recruiter]

Did you check whether the entried re-appeared in there when you say that you deleted the keys in the registry before doing the wuauclt /detectnow /resetauthorization. Can you tell us what way you have applied the reg keys, that is, whether via group policy or via registry patch?

[Dr.pter]

I think that the method wuauclt /resetauthorization and then "restart" and wuauclt /detectnow is not correct, and might be not resulting in the desired effect. Can you try to check that the client is being assigned to the correct target group and also the destination target group appears on the WSUS server, incase not, then the pc will be added to "Unassigned Computers". After that try the correct procedure to use at the time of revoking the SusClientId by following the below method:

1. First of all remove registry entries
2. After that restart Automatic Updates service (a restart of the system does accomplish this)
3. Now try to issue the command 'wuauclt /resetauthorization /detectnow'

[Techguru01]

As per the documentation I think that you will be able to use those 2 switches separately but if you combone them on the same command line then you will need to use that specific switch order.

[Beter 2 Burn Out]

I think that when you are assign computer's to WSUS groups using group policy then it should just re-apear. Or else log on to the client and go to a cmd prompt and type: wuauclt.exe /detectnow . It will tell you why you are not able to communicate with the server.