It's the only Halo game I can't get to connect to Xbox live with and I got a gold account and I heard they shut down the halo 2 servers.i don't believe it bc then y wld they leave all the other halo servers on.makes no sense
Halo 2 was originally released for the very first Xbox console, as such as ran on the first iteration of Xbox Live. The second iteration of Xbox Live launched with the 360 and for a while both services ran alongside one another. Those services were eventually shut down back in 2010 and as such Halo 2 was shut down as well. The only way to play Halo 2 matchmaking now is in MCC.

Regarding the other Halo games, they all launched on the 360 so are set for the current generation of Xbox Live
Thxs stckrboy that actually makes sense.bc they re not current,they pretty much got shut down.
This is only partially true. Halo 2 for vista is not entirely shut down and still connects to xbox live. The only thing that does not work is the multiplayer function but you can absolutely connect your gamertag to it, play the campaign, custom games and unlock all the achievements. Yes even the multiplayer achievements can be unlocked still, this works because in halo 2 for PC you could always unlock multiplayer achievements in custom games so even though the multiplayer servers are down you can still get the achievements by playing the custom games with yourself since GFWL still connects to xbox! =D Let me know if you have any questions and you can see by my gamertag that I am a halo achievement hunter (have every achievement for every halo game across all versions). lol Happy hunting!

*for the overkill achievement you will have to kill your three guests and wait for one to respond before killing the next which was the hardest for me but on a small map with a bit of luck you can do it! =)

This video gives an exact guide for the multiplayer ones: https://www.youtube.com/watch?v=8HkR4YEw7oM