Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello Laik,
I understand your concern and will assist you with this issue.
This issue may occur if there are any remains of corrupt/old Office installation files present on the
computer.
Let's run 'Fix it' from the following article to remove any traces of Office installation and then try re-installing it:
http://support.microsoft.com/kb/2739501
Note: Save the ‘Fix it’ before running it if you’re working on a 64 bit Windows.
Hope it helps. I look forward to your reply to assist you further.
Thank you.