Activating Windows 10 without a manual product key is entirely possible and often legal through Microsoft's modern licensing systems. This guide covers legitimate ways to activate your OS using digital licenses, linked accounts, or troubleshooting tools, as well as what happens if you choose to remain unactivated. 1. Activating via Digital License (Digital Entitlement)
: You can use Windows 10 without activating it, but there are limitations. You'll have a watermark on your desktop, and some personalization options will be unavailable. Moreover, Microsoft might limit some features in the future for unactivated versions.