You can't. It is impossible.
No, in Halo 2 you can not unlock armor.
In halo he wears mark 1 armor in halo 2 he wears mark 2 armor
In Halo 2, Master Chief has Mark VI armor which is an upgraded version of the Mark V armor from Halo 1. If you're looking for the reason why his armor had changed between Halo 2 & 3, I think they just upgraded it, but not enough to call it Mark VII armor.
You can't. It is impossible.
There is two ways to get it #1 unlock all of the armor #2 is to become the highest rank in halo reach
YEZ! real halo armor at ebay.com
by picking up an oversheild
yes you can well in multiplayer anyway
No, there is no armor in Halo 3 that has a knife in the shoulder.
http://hubpages.com/hub/Halo-3-Armor
You have to download a mod, there is no halo armor in the game itself.
Mark IV is a type of armor in the game: Halo 3. This is a evolvement from the Mark V armor in the previous Halo games; Halo:Combat Evolved and Halo 2. The armor is also called the Mark 6. In the game it is an armor that is worn by the main charecter: Master Chief. In the multiplayer game it is an armor that you automaticaly wear in the matches.(there are other armors to wear during matches)