For some reason the eval license won't go away, Office keeps asking to activate yet the MAK license is already activated. This started occurring only after updating Office from Windows update. The license is activated but the activation window keeps popping up.
I removed it and installed our licensed version of Office 2016 Pro Plus. To disable the Office 365 activation pop-up window, we'll have to delete one registry key. Try (Get a free trial of Office 365) Buy (Buy Office from the Microsoft store) Activate (Enter your Product Key or sign in) I presume this pop-up window appears because of the previous Office 365 demo installation that came with Windows 10.