No you need the hard drive and xbox live to play xbox 1 games
No, it is only on the old xbox, but you can play some of the old xbox games on xbox 360 and Halo: combat evolved (halo 1) and halo 2 are two of them.
As far as I know, you can play all original XBOX games on the XBOX 360. It may be different for some of the first XBOX games but both Halo and Halo 2 are playable on the XBOX 360.
No Halo is an Xbox 360 exclusive and not made for the PS3
Yes, my cousins have an Xbox 360 and they have halo one and two for regular xbox and they play it on their xbox
No, you do not need Xbox LIVE to play any original Xbox games. Not all original Xbox games can be played, but Halo and Halo 2 do not need LIVE to be played on the Xbox 360. I just now tried it with my LIVE unplugged and signed in to an offline account and it let me play both of them. The previous answer was a lie, obviously.
You can only play some games if you have the Xbox 360 Hardrive and some console software.
Some work like halo 1 and 2
You don't have to update your Xbox to play Halo Reach. Some games like Forza Motorsport 4 and Homefront will make you update your Xbox.
Some can, but might need an update from Xbox live... the Halo games will run with no problems..
No there are not any halo games available to play online. All halo games are in disk form, available on ps2, Xbox, xbox360. Sorry this was no help to you.
No, because it's an Xbox 360 game. You can't play Xbox 360 games on the original Xbox console.