every since windows 7 came out, fellow Halo 2 fans have been experiencing problems with playing the game. when ever you try to play it, various errors pop up. Their are a few methods of correcting this, but they are all very dangerous, such as deleting vital files from your operating system, and shutting down services through command prompt. one wrong move, and your computer is dead. one right move, and your computer is dead. PLEASE make a patch for windows 7 users, so we can enjoy sweet Halo 2 goodness again 
You have all my support, as a player of Halo 2 PC.
But you have to be more clear and precise, if you want that they fix the bugs.
Are you having troubles with the server browser?
Are you unable to start the game?
Just let us know.
Works perfectly fine for me and I’m running Windows 7…
Although I have heard there can be some complications when installing Halo 2 Vista. I’m all for fixing these!
It was a terrible port and ever since release has been ignored by Microsoft when fans have been reporting bugs and issues. I can’t even run the game on my thousand dollar laptop (which can run BF3 on medium - high) because the game doesn’t recognise my GPU as a GPU (Figure that one out).
tl;dr: Don’t expect any love from Microsoft or 343i in regards to Halo 2 Vista. There have been problems for years and nothing has been done.
I’m sorry for not going into more detail- let me explain. when ever I try to start up the game, it gives me an error, and won’t even go to the loading screen. Here’s the thing- it worked fine for almost a year, which made me very happy considering many people have troubles with this game. out of no where a few days ago, it started giving me errors like it did with my old windows 7 computer! i tried uninstalling it and reinstalling it 3 times, moving my oem*.* files, and many other methods to fix it, but none worked. this makes me a very sad camper. oh so sad 
on the brighter side, I got xlink kai to work, which lets me play halo 2 online through my xbox again :D. If you want to play halo 2 online again, look up xlink kai on google- its pretty amazing.
on the darker side, I still can’t play it on my $800 laptop. makes me want to cry…
Do you have the latest Games for Windows Live?
First try downloading and installing all the latest Updates for Windows/Windows Live/Etc.
Then Try… Removing Malware/Spyware/Trojans/Viruses, Clean up compact and Optimize your PC’s Registry, Fix invalid Shortcuts, Erase your Activity History and Surfing Traces, Clean up Junk Files, Optimize and repair system configuration, Defrag your Hard Disc, Fix Windows Vulnerabilities, Fix Hard Disc errors, Delay start-up items.
It doesn’t have to be in that order. My friend tried this method and it worked for him. I run all the scanners and Cleaners, everyday and my $155 Used Desktop PC, from 2003 runs fine with ZERO problems. And its faster than my dads $2000 Laptop, running Windows 8!