Error connecting to Gamespy (halo trial)?

Everytime I TRY to play Halo Trial in multiplayer, I press 'Get List' (to get list of servers) and nothing happens. After a couple of seconds, an error comes up saying, "An error has occurred trying to contact Gamespy Master Server". How can I fix this?! I can't even host a game because nobody joins even after multiple hours, vs. people joining in a couple of minutes! How can I fix this?

Make sure it's allowed to access the internet through your firewall.

Then reinstall Halo Trial, make sure Gamespy is included with that installation.

Also check if you have an IP address blocker, like Peergaurdian2 or something similar. Usually disabling the program or allowing "IGN Network" in those types of programs fixes the problem.

Check your internet type (open, secured)

try to re-install halo trial because you need to have Gamespy installed to be able to use it. Also, try making a gamespy account for free