I work in a school with 150 XP client computers and 2 windows 2000 domain controllers. im trying to block a certain website from the students who use this client computers. The problem is they keep on accessing this website even when they are having their laboratory classes. I have tried to block it using Group Policy and Internet Explorer - Content Advisor. In Group Policy Ive set it up on user configuration - Windows Settings - Internet Explorer Maintenance - Security - Security Zones and Content Ratings - Content Ratings then checked on Import the current content ratings. But sometimes i still see student able to access the sites that ive blocked in content advisor. What do you think should i do? I dont have access to our firewall to block this sites. i want to block it using just my windows 2000 server. i have heard of using ipsec to block it but i havent tried it yet. would somebody please tell me step by step on how to apply it. thank you so much guys in advance.