Tested on a demo version of the game.
Cheat Codes for Call of Duty 4: Modern Warfare Free Download
In the game, activate the console (option in the menu). Press the [~] (tilde) key to bring up the console, where you enter: 1337 and press ENTER. Then type spdevmap eldaba and press ENTER. This option will start the game in cheats mode.
During the game, press the [~] (tilde) key to bring up the console, where you enter:
give all – All weapons
god – God mode
noclip – Pass through walls
notarget – Enemies can’t see you
give ammo – Full ammunition
jump_height # – Gravity level (default – 39)
timescale # – Game speed (default – 1.00)
сg_LaserForceOn 1 – sets a laser sight on all weapons;
cg_drawGun – remove weapons;
cg_fov – precise aiming works with any weapon;
r_fullbright – brightens the picture;
give weapon name – gives the specified weapon. Here is a list of what can be used with this code: g3, mp5, dragunov, beretta, usp, saw, m9, stinger, javelin