Activation helps verify that Windows hasn’t been used on more PCs than the Microsoft Software License Terms allow.
To activate Windows 7 or Windows 8.1, you’ll need a product key for the version of Windows that’s on your PC. A product key is a 25-character code that looks like this:
PRODUCT KEY: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
How to find your product key depends on how you got your copy of Windows 7 or Windows 8.1:
- If you bought Windows from an authorized retailer, the product key will be on a label inside the box it came in.
- If you bought a new PC running Windows, the product key will be preinstalled on your PC, included with the packaging the PC came in, or included on the Certificate of Authenticity (COA) attached to the PC.
- If you bought a digital copy of Windows from a Microsoft website, the product key will be in the confirmation email you received after buying it.
For more info about how to tell if your copy of Windows is genuine Microsoft software, go to the Microsoft How to Tell website.
Article ID: 15083 - Last Review: Aug 31, 2016 - Revision: 53