We have WSUS running on Windows 2000 Server with 2000 Pro and XP Pro clients.
On a couple of the 2000 clients there is no settings in the registry relating to using WSUS. Normally there are 2 settings I look for:
Under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate there are 2 keys for WUServer and WUStatusServer
Under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate there are 2 keys for AccountDomainSid and SusClient Id
These 2 computer dont have the WindowsUpdate folders from either registry location.
My second question is that there are a couple of the XP clients that will download the updates but not install them unless its done manually. I am using Group Policy on the DC to have it downolad and install the updates automatically.