2. Choose Activate a Product on Steam
3. Click NEXT on the Product Activation window.
4. On the Steam Subscriber Agreement window, click I Agree.
5. Your Product Code for your game should be located inside of the game case on a slip of paper.
Your key will be shown in a white box that says CD-Key. Enter your CD key in the box as shown in the image below.
6. Once you've successfully entered in your CD Key, click NEXT to proceed.
7. Choose whether or not you'd like to have a shortcut placed on your desktop and/or Start menu and then click NEXT.
8. Click Finish to complete the process for adding IL2 Cliffs of Dover to your Steam application.
9. Your game will begin downloading. This can take a long time, the duration of the download will depend on your connection speed.
10. Once your game download completes the download at 100%, you should be ready to click on the Play button to start your game.