These settings allow you to configure Windows client machines to use custom Microsoft Software Update Services (SUS) located on an internal corporate network instead of the Windows Update Internet site.
Open your registry and find or create the key below.
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU]
Create a new DWORD value called “UseWUServer” and set it to “1” to use custom update servers or delete the value to use the default Internet site.
Then open the key
[HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate]
and create two new string values called “WUServer” and “WUStatusServer”, set these values to the names of the custom update servers (e.g. “http://intranetupdate”).
Restart Windows for the changes to take effect.
Note: Information in Microsoft Software Update Services (SUS) can be found online at http://www.microsoft.com/windows2000/windowsupdate/sus/