If your Windows XP clients are not retrieving updates from the SUS server on your network, there are a few things you can try to resolve the problem. First, all of the workstations must be running a minimum of service pack 1 for Windows XP (any Windows 2000 clients must be running SP3).

In order to configure automatic update settings through a group policy, you must import the wuadm template and apply it to the appropriate Active Directory container. Using the policy settings, you can configure workstations to retrieve updates from the SUS server. Use the gpupdate command to manually refresh policy settings on workstations.

You can easily verify of workstations are using the settings configured through the GPO by opening the Control Panel on an XP workstations and double click the Windows Update applet. All the options should be greyed out.

The Windows Update log (%systemroot% directory/folder) will also tell you if the workstation has attempted to contact the SUS server for updates. You can also open the log file on the SUS server to verify that it is retrieving the updates from the Windows Update Web site.