If you run into issues while installing Office 16/ Office 365 on your Windows PC,
Windows provides with a FixTool to remove office from your system and perform a clean install in your system.
The tool can be found at:
https://support.office.com/en-us/article/uninstall-office-from-a-pc-9dd49b83-264a-477a-8fcc-2fdf5dbf61d8
(Link as of 3rd March 2018)
Follow the instructions listed on the page and you should have installed Office completely from your system