Look directly underneath the plastic disc holder or on a sticker affixed to the inside back cover.
If your old key is gone forever, you have two options: buying a new retail code or buying the game via digital storefronts.
Select from the dropdown menu. Click Next and agree to the Steam Subscriber Agreement. Look directly underneath the plastic disc holder or
If you bought the game used or from an unauthorized marketplace (grey-market key resellers), the code is likely dead.
If you want to use the old DVD and avoid Steam entirely (Single-player only, offline): Click Next and agree to the Steam Subscriber Agreement
The Company of Heroes Opposing Fronts product key and retail code landscape has changed dramatically since 2007. While original DVD keys are largely museum pieces today, legitimate digital retail codes are readily available at low prices. Do not fall for keygen scams or grey-market resellers. Instead, enjoy this classic RTS safely and legally via Steam, often for the price of a coffee.
If you lost the physical key, do not despair. Owners of legitimate disc copies can sometimes convert their old key into a free Steam key (see the “Legacy Conversion” section below). While original DVD keys are largely museum pieces
Click on the Games menu at the top of the window.
When you open the installation screen, you are confronted with two separate fields: