I see the date on the post is last june 2011 so its possable the issue of running Halo2 on win7 may have been resolved by now. anyway in case there are any people that haven't court up whith how to fix this little sucker i do have a solution. 1- install halo 2 using the "custom install" option first. do not try to run the game yet!!!! other wise it wont work no matter you do! - next 2 - find the halo 2.exe and set the the compatablity to Vista - not vista 1 or 2. don't run the game yet!! 3 - you need to download the "games for windows client" found on the xbox.com page relating to PC games, save it then run it. http://marketplace.xbox.com/en-US/PC?xr=shellnav you need an xbox account and Tag to play online microsoft games. you need to have the games for windows client runnig for the whole thing to work. once the you have a conection with you xbox account you can now play it. enjoy!!!!!!!!! please forgive me if I have put this little note in the wrong place or if this thing has already been done and dusted. I mean no disrespect to anyone. keith