If you have already installed Halo 2 on your Windows 7 32- or 64-bit and it is not working, go and uninstall it completely. That means also the ‘Games for Windows – LIVE’ runtime which has been installed.
Go and find the current version of ‘Games for Windows – LIVE’ client and install it.
Make sure you have patch MSKB article 976264 and current service pack for Windows 7 installed.
Update your Windows Client Performance Index under
Start/Control Panel/System/Performance Information and Tools/
Now you can install, activate, configure, start and play Halo 2.
Check for Halo 2 update and install it.