Sid Meier's Civilization IV: Colonization is the third offering in the award winning Civilization IV series. A re-imagining of the classic Colonization game Sid Meier created in 1994, Sid Meier's Civilization IV: Colonization is a total conversion of the Civilization IV engine into a game experience in which players will lead a European...
Open the Steam client, login and locate the Games tab on the top menu. Click this and then select “Activate a Product on Steam…”
Enter your unique code that's displayed on the 'Orders' page of CDKeys.com and follow the prompts to activate.
Your game is now viewable in the “Library” tab and is available to download/install when you’re ready. You can find additional support for the Steam client here: https://help.steampowered.com/en/wizard/HelpWithSteam