Since normal uninstallation isn't working, use the Microsoft Support and Recovery Assistant (SaRA) to force-remove all Office installations.
After using SaRA, manually check and remove leftover files:
Navigate to these directories and delete any leftover Office-related files:
C:\Program Files\Microsoft Office
C:\Program Files (x86)\Microsoft Office
C:\ProgramData\Microsoft\Office
C:\Users<YourUsername>\AppData\Local\Microsoft\Office
C:\Users<YourUsername>\AppData\Roaming\Microsoft\Office
In Start Search type Regedit and press the Enter key.
Navigate to these keys and delete any Office-related entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office
HKEY_CURRENT_USER\Software\Microsoft\Office
Reboot.
Reinstall Office.