You create a WSUS GPO and apply it to the Computers.
Now how do you validate its working
Open the registry and browse to :
computer\HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate
The GPO for WSUS should populate the registry with following values
WUServer …updates server
WUStatusServer…update
UpdateServicesURLAlternate
These values should match the GPO settings for WSUS.
