Well... When I try to launch my MW2 Multiplayer, it starts up fine... but then it full screens into the top left of my computer monitor and stays there... like this (but it's full screened on my computer)
I also now notice that all the pictures that move (gif's I guess) only move when I'm typing or moving my mouse... Graphical error? :/
Go to your mw2 players folder and delete this file:
W7: Program Files (x86) > Steam > steamapps > common > modern warfare 2 > players > config_mp.cfg
Next run mw2. It should auto update a new config_mp.cfg. If it does not work then go to steam > games library > right click mw2 > properties > local files > verify integrity of game cache.