How to uninstall a Windows update in Windows 2003

Disable the group policy allowing the notification to non-admins:

Computer Configuration > Administrative Templates > Windows Components > Windows Update > Allow non-administrators to receive update notifications

But, this behavior is the default - so either someone's specifically enabled this policy in the past, or the users are admins?

Check the windows update settings and assure that the system is set to NOT download updates. If it has downloaded already, there will normally be an icon on the notification area indicating they are ready to install. However, you need to manually initiate the install. If someone has done this, the next reboot will complete the process. Again, the icon in the notification area will pop up a warning about the system needeing a restart to finish an update. If the system is set to install automatically, it would likley have rebooted.