This is a simple fix to repair a licensed copy of Microsoft Office 2013 that keeps appearing as an unlicensed copy. This generally occurs with subscription licensing through Office 365.
- Make sure all Office programs are closed
- Open the Command Prompt as Administrator
- Navigate to the Office Installation folder %ProgramFiles%\Microsoft Office\Office15
- Run “cscript ospp.vbs /act”
The ospp.vbs script has many other switches to check the status of the Office install. Please refer to the reference script for more information.
Let me know if this works for you in the comments below.