Activation helps verify that your copy of Windows is genuine and hasn’t been used on more devices than the Microsoft Software License Terms allow. Depending on how you got your copy of Windows 10, activation will use either a digital license or a 25-character product key. A digital license (called a digital entitlement in Windows 10, Version 1511) is a method of activation in Windows 10 that doesn't require you to enter a product key.
During installation, you’ll be prompted to enter a product key if no digital license is found on your computer. A valid product key or digital license is required to activate Windows 10; without one, activation can’t continue.
To find the activation method that works with your copy of Windows 10, see the table below.
| If you got Windows 10 by... | Activation method |
|---|---|
| Upgrading to Windows 10 for free from an eligible device running a genuine copy of Windows 7 or Windows 8.1. | Digital license |
| Buying genuine Windows 10 from the Microsoft Store and successfully activated Windows 10. | Digital license |
| Buying a Windows 10 Pro upgrade from the Microsoft Store and successfully activated Windows 10. | Digital license |
| Being a Windows Insider and upgrading to the newest Windows 10 Insider Preview build on an eligible device that was running an activated earlier version of Windows and Windows 10 Preview. | Digital license |
| Buying a copy of Windows 10 from an authorized retailer. | Product key (On a label inside the Windows 10 box. A digital license will be given to your device for Windows 10 based on the valid product key you entered. If you bought your PC from a manufacturer, the manufacturer, not Microsoft, must provide you a product key.) |
| Buying a digital copy of Windows 10 from an authorized retailer. | Product key (In the confirmation email you received after buying Windows 10 or in a digital locker accessible through the retailer’s website. A digital license will be given to your device for Windows 10 based on the valid product key you entered.) |
| Having a Volume Licensing agreement for Windows 10 or MSDN subscription. | Product key (Available through the web portal for your program.) |
| Buying a new or refurbished device running Windows 10. | Product key (Preinstalled on your device, included with the device packaging, or included as a card or on the Certificate of Authenticity (COA) attached to the device. If you bought a refurbished PC, the refurbisher, not Microsoft, must provide you a product key.) |
For more detailed information, expand a topic in the list below. If you need to install and activate Microsoft Office, see Download and install or reinstall Office on your PC or Mac.