Buy Tom Clancy's Splinter Cell Chaos Theory®

Uplay is Ubisoft's Download Platform. If you still don't have the client, you can download it HERE, install it, and create a Uplay account if you don't have one already. Then you will have to get the Download Manager related to your game, unzip its content and use the .exe file which will download your game. At last, once the download is over, you just have to get back on Uplay where you will see your games cover and click it to activate your CDKey.

You can download your game using the CD Key on the retailer or publisher website. Please follow the steps and instructions given by the retailer.

For Steam CD Keys, you must download (HERE), install the Steam software and create a new account. If you already have a Steam account, once you log in, click "Add a game" (located in the bottom left corner), and then "Activate a Product on Steam". After a few more clicks, you will be prompted to type in your CD Key. Thus, the game will be activated and automatically added to your account library.

This is the Epic Games launcher. You must download the client HERE, install it, and then create your account. When you sign in to your account, click on your avatar and then on "Redeem Code". Enter your Cd Key your game, your game will automatically be added to your library, and the download will start.