Retail Microsoft product keys are usually on a bright sticker located inside the case ... entitlement if you upgraded your PC from Windows 7 or 8.1 for free. You will also have a digital ...

the sticker is typically affixed to the computer tower. Look below the barcode on the Certificate of Authenticity to find your Windows validation code, which is listed as "Product Key." ...

The biggest change is the absence of a product key, which was included on the holographic Certificate of Authenticity (COA) sticker with PCs that came pre-installed with Windows 7 or earlier versions.