The best-selling first person action series of all-time returns with the epic sequel to multiple “Game of the Year” award winner, Call of Duty®: Modern Warfare® 2. In the world’s darkest hour, are you willing to do what is necessary? Prepare yourself for a cinematic thrill-ride only Call of Duty can deliver. The definitive Multiplayer experience returns bigger and better than ever, loaded with new maps, modes and features. Co-Op play has evolved with all-new Spec-Ops missions and leaderboards, as well as Survival Mode, an action-packed combat progression unlike any other.

Go to: http://store.steampowered.com/ and download STEAM client Click "Install Steam" (from the upper right corner) Install and start application, login with your Account name and Password (create one if you don't have). Please follow these instructions to activate a new retail purchase on Steam: Launch Steam and log into your Steam account. Click the Games Menu. Choose Activate a Product on Steam... Follow the onscreen instructions to complete the process. After successful code verification go to the "MY GAMES" tab and start downloading.