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.

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.

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 …

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.

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 …

Learn how to activate Office that is pre-installed on new Windows 10 PCs or using a new product key.

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 …

See how to activate Office 2016 for Mac using a single license or multiple licenses.

To find your Windows product key, see Find your Windows product key. If you have a digital gift card that's good for a game or app, see Redeem a gift card or code to your Microsoft account.