Most repacks contain RELOADED or SKIDROW cracks. If the game asks for a CD key, copy the cracked .exe from CODEX or Crack folder to the main game directory.
If you find a reputable source (like trusted repackers), follow these steps: call of duty modern warfare 2 highly compressed pc work
Even if the download size is small, the game still requires your PC to process the original graphics. Ensure your system meets these minimum specs: Most repacks contain RELOADED or SKIDROW cracks