Halo: Combat Evolved Cheat Codes for PC

Shoot through wall:
In multi-player mode, drive any Warthog close to a building so that the side of it is touching. Get in the gunners turret and turn it towards the wall. If done correctly and you are close enough, you should be able to to shoot at an enemy through the wall and not receive damage from them if they shoot back.

Cheat Codes
These cheats are ONLY for the Custom Edition of Halo: Combat Evolved. Open the properties window of the Halo shortcut and add " -console -devmode" to the end of the target field. Apply changes and start the game using that shortcut. Press [~] during game play to display the console window, then enter one of the following codes to activate the corresponding cheat function (codes do not work in online games):

cheat_medusa <0 or 1> - Instant deaths for enemies that see player
speed <0-20> - Set game speed game
cls - Clear console window
cheat_bottomless_clip <0 or 1> - Unlimited ammo and no overheating for weapons
cheat_infinite_ammo <0 or 1> - Unlimited ammunition
cheat_super_jump <0 or 1> - Super jumps
cheat_bump_possession <0 or 1> - Possess touched character
cheat_deathless_player <0 or 1> - Invincibility
cheat_spawn_warthog - Spawn Warthog
cheat_all_powerups - Spawn all power-ups
cheat_all_vehicles - Spawn all vehicles
cheat_all_weapons - Spawn all weapons
cheat_teleport_to_camera - Teleport player to current camera position
quit - Quit game

Super-Marines
Kill Captain Keyes on "The Pillar of Autumn"

Different Ending
To get a different and longer ending movie Halo, beat the final level on Legendary.

Hidden Music
Near the end of the 5th level (Assault on the Control Room), snag a Banshee in the open area and head up to the Control Center. There are three ledges that bracket the central pillar in front of the door; you want the middle one. You can land your Banshee parallel to the walkway, facing the left (with respect to the door), and hop out the back. Be careful - if you're not perfectly straight, you'll hop out to your death. Walk to the right end of the ledge... and stand still. You should hear this soft, sorrowful music playing.

Hidden Area
In the chapter where you must find Capt. Keyes in the swamp, there is a secret area you can access right from the beginning.

When Foe Hammer says ''The Last transmission from the captain's dropship was from this area. That was over twelve hours ago'', immediately start pressing your grenade throw button. whatever you do, DON'T MOVE! After a few seconds, the dropship will take back off, and you'll still be in it! It flys for about 20 seconds then crashes. Press ''X'' to exit the dropship.

Now walk directly away from the ship until you reach a clearing. Head towards the center and out of the fog you'll see a lone Marine standing there! He won't move or say anything, unless you shoot him in the foot w/ your pistol.
Just so you know, the name of this masterpiece is called The Siege of Madrigal, and it can be found in Bungie's earlier game, Myth. It was written by Marty O'Donnell from Total Audio.

Getting past invisible walls
This glitch only works in co-op.

1. Go to The Silent Cartographer.
2. Kill all the enemies at the landing site.
3. After they are all dead, wait for the warthog to be dropped.
4. Get into the warthog with your team mate and drive into the water.
5. Keep driving until you hit the invisible wall.
6. Have one of you two stand as close to the wall as possible.
7. Back the warthog up a little bit.
8. Slowly drive into your friend and push him back.
9. The game should skip for a second, and you can then run past the invisible wall.

If you move the warthog too fast, you will kill your friend. This can be done on any level where there's a warthog and an invisible wall.

Getting on Top of Sidewinder
First of all create a new multiplayer game in which your shields and life are the maximum they can reach. After creating this go into the game and also go into the level Sidewinder. When you are in the level get a rocket launcher and plasma grenade, and travel to the Blue Tower Base. Go to the top of this base and then go through the teleporter. When on the other side keep walking until you are around the bend. When you get to the end of the bend there should be another room with a teleporter in it and from the outside there is a border to the room in which you can jump on (looking at the room from the outside!). It may take a few tries but you will get up there (you can also take a vehicle up there with you for easy access to the top of the border). Once you make it up onto the border go to the end of it and looking down slowly walk backwards and get a grenade caught on your foot. As soon as you get the grenade on your foot shoot the rocket launcher down at your feet. The lift should send you flying pretty high. When you first start flying through the air push both joysticks in the dirrection of the wall that you are attemting to get upon. This may take many tries, although it is very frustrating once you get the hang of it, it can be much fun.

How to get a banshee into a cutscene
:CO-OP only:On the level assault on the control room,at the last open area,when you come out onto a bridge and there are some grunts, some elites and two banshees; run really quickly to one of them while your parner kills the covent. Get in and fly to the really big door that is the beginning of the last part of the mission. Your partner can kill himself and respawn there for the sake of speed.Open the door and kill all the covenant untill you get to the last door(the one before the final cutscene of that level). While one person opens the door the other should fly at it with the banshee (this takes timing, get a save point before you try it), and start from there again if you mess up. If done correctly the banshee will be in the cutscene as it starts. If you are really lucky then the banshee may run over MC during the cutscene!

Unlimited Camo Trick
Select the ''Assault on the Control Room'' level on any difficulty in Co-Op mode. Next, skip to the part where there are two tanks, and a banshee flying over you just before a cave. You'll notice a cloak to the right of the tunnel next to some ammo. Keep Player 1 by the cloak, and have Player 2 beat the entire part just before you trigger the ''Rolling Thunder'' loading zone after the bridges. Now have Player 1 actually go cloaked and at that point Player 2 should walk through and trigger the ''Rolling Thunder'' loading zone. Player 1 will be spawned all the way down by Player 2 and for the rest of the level be cloaked without it ever wearing off. The only way it will wear off is if Player 1 (not 2) dies.

Unlimited Rockets
Select the ''Assault on the Control Room'' level on any difficulty in Co-Op mode. Next, skip to the ''Rolling Thunder'' loading zone after the bridges part. Have Player 1 fire a rocket in any direction. Now, at the same exact time, Player 1 should reload the rocket launcher and Player 2 should walk through the loading zone. Player 1 will now have unlimited rockets until the end of the level. This trick will wear if it Player 1 dies, reloads, or switches weapons.

Three guns on the first level
Towards the beginning of the game, there is a way to bypass the two weapon limit and carry three weapons at once. On the first level, make your way to the bridge. After speaking with the captain, quickly run out of the bridge before the chapter name disappears. If you were fast enough, the checkpoint at the door will not trigger. Now run to the mess hall and get your Assault Rifle and another weapon. Now, run back to the bridge and trigger the checkpoint. When you go back towards the mess hall, the pistol will appear in your hands, and you will be carrying three weapons instead of two. Each gun reloads and exchanges normally. Note: This only lasts for the first level.

Hint
Get into a machine Gun Warthog and drive to a rock on the right hand side of the base with the big dark hill in the corner and park it backwards on it and get into the gun and jump off and try to get into the rock... this will allow you to shoot people but not be seem or shot back
submitted by: Will