Windows 8.1 Pro Product Key – Activation Guide You will receive one (1) Windows 8.1 Pro product key, valid for activating a single PC. These keys support lifetime activation and can be reused on the same computer after a system reinstall. 🔐 How to Activate Windows 8.1 Activating your copy of Windows 8.1 ensures full access to all features and confirms you're using genuine software. Follow th...