Turn On CONSOLE on the settings then type ~ in-game to enter codes:

TURNS ON CHEAT sv_cheats 1
UNLIMITED AMMO sf_use_ignoreammo 1
SPEED g_speed 190
GRAVITY g_gravity 800

TURNS ON FPS /cg_drawfps 1
WINDOWS MODE \r_fullscreen 0 and \vid_restart

CHEAT CARDS ON ZOMBIE MODE:
1) Choose the map as you normally would.
2) Once you're back in the PUBLIC MATCH room, go back to settings (GAME SETUP).
3) Click GAME MODE: Campaign Co-op then click GAME MODE SETTINGS.
4) Click DEATH CARD CHEATS ENABLED then click SELECT CHEATS
5) Enabled any card then click ACCEPT.
6) BACK, BACK you should be in PUBLIC MATCH room with a card.

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Multiplayer Profile: only the username is stored online with the cd key, all other information (eg. levels, perks & prestige) are in hard drive. Make sure to back up the files when formatting or installing a new copy of CoDWaW on another computer.

C:\Documents and Settings\YourPcName\Local Settings\Application Data\Activision\CoDWaW

or vista c:\Users\YourPcName\AppData\Local\Activision\CoDWaW