Why can't i play multiplayer for Halo Combat Evolved (CE) for pc?

When I try to push the button to get the list, it will say something like this: "An error has occurred trying to contact the Gamespy Server." or something like that. I'm not sure why it says that because my laptop is fine, it can run games like Call of Duty 4 no problems. Someone PLEASE help me out!

Your router or firewall probobly has the specific Game Server on the Not Trusted list. You should probobly call the help line to get the specific name for the Server so you can put it on the allowed list