You can use the same KMS key to activate Windows 10 and Office 2019.
If you have a KMS host computer configured to activate Windows, you can configure that same KMS host computer to activate Office.
You can also configure a KMS host computer to activate multiple versions of Office, such as Office LTSC 2021, Office 2019, and Office 2016. 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'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.
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