Your Windows 10 product key may be necessary to unlock all features -- but it's not easy to find. Here's where to look for the product key (even if it's lost).

Windows remains functional without activation, but you'll be locked out of personalization and other non-essential features until it's addressed.

Different ways to find your Digital License or Product Key in Windows 11/10. Retrieve Physical key or Digital license linked to Microsoft Account.

The very first thing that you need to do when trying to fix activation error code 0xc004f063 is to run the automated Windows Activation Troubleshooter.

Product key and activation with Windows 10 free upgrade: When you upgrade your PC to Windows 10 from Windows 8 or 7, your licence will be tied to the hardware upgrade, not to the Microsoft account.

Fix Error 0xC004C003, 0xC004C003, The activation server determined the specified product key is blocked, on Windows 11/10, by following this guide.

Microsoft introduces a tool to help you keep your free Windows 10 upgrade after you swap out your motherboard.

Here are a few more answers to some nagging questions about Windows 10 upgrades and activation in the post-Anniversary-Update era.

On Windows 10, you can reactivate your computer after a significant hardware change, such as after replacing a motherboard, hard drive, or processor, and in this guide, I will show you how.