If you do not have a product key, or it's the first time to install Office 2016 on your computer, you may need to buy an activation key for your Office Program. If you have a license key for MS Office 2016, enter it on the text box to finish the installation.
You may need to reinstall or install Microsoft Office 2016 on your computer, and during the installing process, you are prompted to enter a 25-character product key. 3 ways to check and view MS Office 2016 Product Key
