Learn how to activate Windows using a product key or digital license, check your activation status, and link your Microsoft account.

Locate your product key for Windows 10 or Windows 11. Depending on how you got your copy of Windows 10 or Windows 11, you'll need either a 25-character product key or a digital license to activate it.

In Windows 11, it is essential that you link your Microsoft account with the Windows 11 digital license on your device. Linking your Microsoft account with your digital license allows you to reactivate Windows using the Activation troubleshooter whenever you make a significant hardware change.

Windows activation requires either a 25-character Windows product key or a Windows digital license. Find out which activation method your device uses and where to find it.

How is activation related to genuine Windows software? Activation helps verify that your copy of Windows is used only on PCs that the Microsoft Software License Terms allow. It pairs your product key or digital entitlement with your hardware configuration.

This issue might occur when you try to activate the operating system with an OEM Activation 3.0 (OA3) Digital Product Key (DPK). Error 0xC004C003 occurs when a licensing code component tries to access a registry hive without proper access.

When you try to activate Windows 7 or Windows Vista, you may receive an error message that is accompanied by an error code and its description. This article will guide you through step-by-step methods to help you resolve your problem.

Activation is an anti-piracy technology that verifies the product key for the copy of Windows 7 that is running on your computer. The product key is a 25-character code that is located on the Certificate of Authenticity label or on the proof of license label.

This article defines product activation and describes when and how to activate a Microsoft product. It also explains how to contact a Microsoft Product Activation Center and contains additional product activation resources.

Activate Microsoft 365 or a non-subscription version of Office. When you start an Microsoft 365 app that's not activated, you'll be prompted to sign in to Microsoft 365. Be sure to sign in using the Microsoft account, or work or school account, that you used to buy or subscribe to Microsoft 365.