Before proceeding with Activation make sure you already download and install the Steam app. Download and Install Steam Client from this link: https://store.steampowered.com/about To Activate a Steam CD Key follow this: 1.Launch the Steam App 2.Login to your account 3.Click on the Game Menu 4.Select "Activate a Product on Steam" 5.Follow...

In case you don't have Windows 10 Pro or Home already downloaded and installed you can do it from here: https://www.microsoft.com/en-us/software-download/windows10 Entering the CD Key Click on Start icon in the Taskbar -> Go to Settings Click on Updates & Security -> Select Activation from Left Side Enter the license key...