Learn how to find a Windows product key for activation, and when you'll use a digital license instead.

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

Learn how to find a Windows product key for activation, and when you'll use a digital license instead.

A product key is a 25-character code that's used to activate Windows and helps verify that Windows hasn't been used on more PCs than the Microsoft Software License Terms allow.

In summary, a product key is used during installation, while an activation code is used to activate the software afterwards. Both are essential for ensuring a legitimate and functional software experience.

Learn how to upgrade from Windows 10 Home to Windows 10 Pro or Windows 11 Home to Windows 11 Pro, including how to use a valid product key or the Microsoft Store.

When you get a message that says Windows can't be activated, there are several possible reasons why. Select any of the following topics to see some typical reasons for activation difficulty, along with …

If your purchase of Office or Microsoft 365 came with a product key, you enter your product key on one of the websites listed below for your product. After you enter your key, you can download and install …

If you make significant hardware changes on your device, such as replacing your motherboard, Windows will no longer find a license that matches your device, and you’ll need to reactivate …

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 …