1.Download and Install Steam: Steam
2.After the Download is complete run it and install it. 3.Once Steam is installed, open it and log in with your username / password (create one if needed). 4.Once logged-in click "+ Add a game" in the bottom left corner of your Steam app (Or use the "Games" tab in the main menu).
5.Select "Activate a Product on Steam..." 6.A new window will ask you to accept the "Steam subscriber agreement". Click accept.
7.After that Steam will prompt you to enter the code you purchased on GK4A 8.Steam will now authenticate your code after a few seconds.
9.After the activation is complete the game will be visible in your list.
10.Click it to start the download.If you require more specific help, or if you have any questions, don't hesitate to to Contact us by Chat or normal contact form.