If you’ve used Office for a long time, you probably remember buying an Office disk and product key and storing them in a safe place after installation in case you needed to reinstall. As long as you had your product key, you could install and activate Office on a new device. This is the way things worked for a long time, but times have changed and we’ve modernized how Office is licensed and activated. Today, when you buy the latest versions of Office or Microsoft 365, some stores provide a card with your product key on it.
For other stores, your product key might be printed on your receipt or sent in an email.
Once you have your product key, you enter it at microsoft365.com/setup, and your new Office product is added to your Microsoft account. If you don’t have a Microsoft account, you can create one. Now that you’ve used your product key, you no longer need it. Instead, your Microsoft account becomes your key to installing and activating your Office products. This is why it’s important to remember the email address and password for your Microsoft account.
Your Microsoft account is used to access account.microsoft.com/services, where you can install Office. Your Microsoft account is also used to activate Office, which you do by signing in when prompted. With Office and your Microsoft account, you can start creating your best work.