taken from bashandslash.com
ever wanted wanted to turn off that happy music and background noises? well heres now!
Simple.
Rename the miles sound folder in your
C:\Program Files\Activision\Call of Duty 4 - Modern Warfare
directory.
You can rename it anyway you please. This is what we did:
C:\Program Files\Activision\Call of Duty 4 - Modern Warfare\nomiles
That's it...no more music.
