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

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.

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.

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. This article will help you troubleshoot and fix common activation errors in Windows.

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. This article will help you troubleshoot and fix common activation errors in Windows. For help finding your product key, see Find your Windows product key.

What to try if you can't install or activate Office for Mac. You can find troubleshooting steps for common installation or activation issues for Microsoft 365 for Mac here. If the issue you're having is not in these lists, you may also be experiencing an emerging issue.

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 you're unable to activate Windows 10, the Activation troubleshooter could help. To use the troubleshooter, select Update & Security. option is available only if your copy of Windows 10 (Version 1607 or later) isn't activated. Once you activate, the option disappears.

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.

Run the Windows 10 Activation Troubleshooter: select Start > Settings > Update & Security > Activation and then select Troubleshoot. Check if you have a paper copy of your Windows 25-character product key you can enter to activate Windows 10.