PLZ HALP!!!

I’m on Halo: CE Pc TRIAL, but whenever I start my own game, people are unable to join. It used to work, but then it suddenly stopped. I look on other people’s computers and my game either doesn’t show up on the list, or it says it’s unable to join. This is the free trial version I got from http://www.gamefront.com/files/1143930/Halo-Combat-Evolved-Demo/ that only alows me to play on blood gulch. I also tried to update the patch at http://hce.halomaps.org/index.cfm?fid=4987 but when I got it it said that I didn’t have halo installed on my computer. I think this is because I have the halo trial.
Plz Halp!
:frowning:

Other people have to have the trial.

Yes, the other people have the trial too but it still doesn’t work.
PLZ HALP!
D: