If Microsoft keeps prompting for activation after it has been install from business premium account from the Office365 portal.
Please can you follow through the the below guide as the error code indicates existing Microsoft services installed.
Ensure all office applications are closed before running the below.
1. Open a command prompt as Administrator
2. In the command prompt, type the following:
Office 2016 (32-bit) on a 32-bit version of Windows;
cscript "C:\Program Files\Microsoft Office\Office16\OSPP.VBS" /dstatus
Office 2016 (32-bit) on a 64-bit version of Windows;
cscript "C:\Program Files (x86)\Microsoft Office\Office16\OSPP.VBS" /dstatus
Office 2016 (64-bit) on a 64-bit version of Windows;
cscript "C:\Program Files\Microsoft Office\Office16\OSPP.VBS" /dstatus
3. You should now get a screen with some license details such as the license name, type and the last 5 characters of the Product Key.
You can use the last 5 characters of the Product Key to remove it using command:
Office 2016 (32-bit) on a 32-bit version of Windows;
cscript "C:\Program Files\Microsoft Office\Office16\OSPP.VBS" /unpkey:
Office 2016 (32-bit) on a 64-bit version of Windows;
cscript "C:\Program Files (x86)\Microsoft Office\Office16\OSPP.VBS" /unpkey:
Office 2016 (64-bit) on a 64-bit version of Windows;
cscript "C:\Program Files\Microsoft Office\Office16\OSPP.VBS" /unpkey: