Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
That error occurs because there was previously a volume licence version of Office installed on your PC and the entry for that needs to be removed form the registry.
1
Please follow these steps carefully.
Click your Start Button, type regedit and hit Enter to open the Registry Editor.
Click View and make sure 'Address Bar' is turned on.
Paste this into the Address Bar at the top and hit Enter.
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Office\16.0\Common
In left pane of the registry editor, expand the Common folder, there should be a sub folder named OfficeUpdate
Right click and delete the OfficeUpdate Key
Close the registry editor and restart (not shut down) your PC to apply the change.
2
If that does not resolve the problem, please follow these steps carefully.
Open the Registry Editor again.
Paste this into the Address Bar at the top and hit Enter.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun
In the left pane of the Registry Editor, is there a sub-folder of ClickToRun named Configuration?
If there is, right click that Configuration key (folder) and delete it
Then, restart (not shut down) your PC and try running the installation again