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

Activate a brand new Office product key. Troubleshoot activation errors. 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.

Activation helps verify that your copy of Windows is genuine and hasn’t been used on more devices than the Microsoft Software License Terms allow. There are three methods to which you can activate your product: Online via the internet, by telephone using our automated systems, and by a live support advocate.

Activate Windows 7 or 8.1. Find your Windows product key. Learn how to troubleshoot and resolve 'Windows can't be activated' error message.

If Office activation fails, you'll see Unlicensed Product or Non-commercial use / Unlicensed Product in the title bar of your Office apps, and most features of Office are disabled. To restore all features of Office, you'll need to fix the problem that's causing activation to fail.

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.

Provides several workarounds to the Windows activation or validation error code 0x8004FE33 when you connect to the Internet through a proxy server that uses Basic authentication.

If you need help activating Microsoft 365 or Office, see Activate Microsoft 365 or Office for Mac. If activation fails, see What to try if you can't install or activate Microsoft 365 or Office for Mac.