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.

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 …

Learn how to redeem a gift card, code, or Office product key and spend your balance at Microsoft Store online, on Windows, or Xbox.

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 …

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

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.

Get help with product key errors, or geographical region errors, when you redeem a new Office product key on Office.com/setup.

A BitLocker recovery key is needed when BitLocker can’t automatically unlock an encrypted drive in Windows. This key, which is a 48-digit number, is used to regain access to the drive.