You need one of the three to start; Xbox 360 Transfer Cable (http://www.excheap.com/brand-new-xbox-360-hard-drive-transfer-cable-kit-p-913.html), XSATA (http://us.codejunkies.com/Products/XB360-XSATA__EF000192.aspx), or Xport 360 (http://us.codejunkies.com/Products/XB360-Xport___EF000191.aspx). These three things allow you to access your 360 HD from your computer. Then you need a number of modding programs. Halo Tool Box (http://www.se7ensins.com/forums/halo-3-modding-programs/119664-halo-tool-box.html) has everything you will ever need. The rest is up to you and Google to find out how to actually do it all.
Forge mode
With that magical feature called Forge.
go to the forge sign in the title screen
No, not unless you modify the game
halo 3 obviously
Halo 3: ODST is the newest of the two, but not the newest Halo game.
The halo time line goes Halo Wars, Halo: Reach, Halo:CE (halo 1), Halo 2, Halo: ODST, Halo 3. Halo 3 and ODST are practically at the same time.
After Halo 3 there was halo wars, halo 3 ODST, and Halo reach. A new company (not Bungie) will be making a Halo 4 and rumor has it there will be a remake of Halo Combat Evolved.
Halo 3 ODST is not for PC but Halo 1 and maybe Halo 2-3 are
it goes halo, halo 2, halo 3, halo 3 odst and soon halo reach will be available
Halo Games: 1. Halo: Combat Evolved (Xbox, PC) 2. Halo 2 (Xbox, PC) 3. Halo 2 Muliplayer Map Pack (Xbox) 4. Halo Triple Pack (Xbox) 5. Halo 3 (Xbox 360) 6. Halo 3 O.D.S.T (Xbox 360) 7. Halo reach (Xbox 30) Other Halo Games: 1. Halo Zero (PC) 2. Halo: Custom Edition (PC) Future Games: 1. Halo Wars (Xbox 360) 2. Halo: Chronicles (Xbox 360) 3. Halo 3: Recon (Xbox 360)4. Halo 3: ODST (Xbox 360)
the same way in halo 3 because when you play halo 3 mythic it says your playing halo 3