The Disc Read error is one of the more annoying bugs to deal with in Modern Warfare 2 since it does not have a permanent fix. It usually occurs if the shooter's servers are acting up or if there are corrupt files in the game's installation directory.
Inspect and clean the game disc.\n\n Excessive scratches or smudges can prevent your console from reading a disc. If there are no scratches, then clean the disc. Here's how: Hold the disc by the edges without touching the top or bottom surfaces.