Office LTSC 2021: At least Windows Server 2016 or at least Windows 10 (volume editions).Office supports KMS host computers running on the following operating systems, depending on which version of Office is being activated by KMS: You'll also need to install the Office Volume License Pack for each version of Office on the KMS host computer and activate a KMS host key for each version of Office. In these cases, the KMS host computer must be running an operating system that supports KMS for each of the versions of Office that you want to activate. You can also configure a KMS host computer to activate multiple versions of Office, such as Office LTSC 2021, Office 2019, and Office 2016. If you have a KMS host computer configured to activate Windows, you can configure that same KMS host computer to activate Office. Then, you need to activate the KMS key over the internet or by telephone. To enable the KMS host computer to activate Office, you must install the Office Volume License Pack and enter your KMS key on the KMS host computer. You can configure a Windows Server computer to be a KMS host computer by installing the Volume Activation Services role and then running the Volume Activation Tools wizard. To activate volume licensed versions of Office, including Project and Visio, you must have a Key Management Service (KMS) host computer.
Applies to: Volume licensed versions of Office LTSC 2021, Office 2019, and Office 2016 (including Project and Visio)