No, We recommend that you uninstall any previous versions of Office before installing Office Professional 2021.
To help you uninstall versions of Office you should use the official Microsoft unistall tool.
This is not a problem or error.
As the office licenses are reclaimed/refurnished from end of life PC hardware, they require a direct transfer.
Simply choose to "activate via telephone" and you will be given your "installation ID".
Simply visit Lizosoft's activation center and enter your "Installation ID" and our system will verify your license.
If your license is authorized you will be shown your "Confirmation ID" to activate your license.
You can see our video tutorial located here.
Please type a valid Installation ID for your office product.