Yes. However, you must make sure that the version of Halo 2 you are trying to play is the PC edition rather than the XBOX version. It should read "Halo 2 for Vista" or something similar. Now this does NOT mean it is only compatible with Vista. Halo 2 is compatible with Windows Vista and Windows 7, but not Windows XP.
No, if it is compatible with Windows 7 Professional it will be compatible with all versions of Windows 7.
Yes, it is compatible with Windows 7. I installed and have played it for hours and hours.
Yes because it works on my computer and I have Windows 7.
Sadly no, you can only play it on Xbox 360.
no
Yes.
yes, from windows XP to windows 7, but only windows!
Yes, Microsoft Office 2003 is compatible with Windows 7.
Yes, Flight Simulator X is compatible with Windows 7.
Yes. Halo 2 runs on everything from Windows Vista and newer (which would include Windows 7).
As of July 2013, Roller Coaster Tycoon 3 Platinum is compatible with Windows 8 if it is set to Windows 7 compatibility mode. This tricks the game into thinking it is running under Windows 7 and allows it to function normally.