Originally Posted by Ganzor
Edit: This works with 1.0.169 and 1.0.172.
Instructions: Load the trainer and the game (doesn't matter which order) and then press the buttons on the trainer corresponding to what you want to change.
Notes: If you do it at the main menu, occasionally you will get a profile lock (stats wont save when you close the game), but if you start a private server and then press the buttons on the hack, you will guarantee having no problems with stats saving and will help with looking legit. If you do change your stats when on a private server, take note that you won't see the changes until you leave the server.
Play in windowed mode (easy alt+tabbing):
Navigate to ~Steam\SteamApps\common\call of duty modern warfare 2\players\config_mp.cfg
Change r_fullscreen to 0 for windowed mode, or 1 for full screen.
Load MW2 and it will be windowed if you set r_fullscreen to 0 :-)
Also, this is meant for multiplayer and is undetected.