I failed, I was so eager to get started with the PC version of MW2 that I clicked to not play the 'airport' level. Is there any way to get it back? I've checked config files and the in-game options but nothing. Do I have to reinstall?
You could wipe the game from your hard drive. You would have to start again but I think Multiplayer ranks are stored online so you 'should' only lose single player progress.