Enabling Content Advisor in Win2K Prof

How do you block sites in Content Advisor in IE 5.5 on a stand-alone Win2K Professional and have the settings take effect on all users? My technical team and I have been wrestling with this, and by using a user account with admin rights, the settings will take effect. However, if you log on using an account with Restricted User access level, the settings will not take effect, and you will be able to access the sites you have blocked under the user account with admin rights. Implementing Group Policy doesn’t resolve this either. Your help will be highly appreciated. Thanks!