Just as an update, and to conclude: I completely removed Office 365
and Office Professional Pro 2010 with the Easy fix tool supplied by Microsoft:
https://support.office.com/en-ie/art...c-2fdf5dbf61d8
This worked smoothly, after failed attempts via Control Panel.
After backing up my files to an external hard drive, I re-installed Windows 10 Pro, which deleted all my folders/files, as expected. Installation and updates took close to three hours, over Wifi.
I then re-installed Office 365 (64-bit) via my Office 365 college account which took around 25 minutes. In the process of copying back the files I need, and all is working smoothly: Excel, Word etc.
Thanks for your help and advice Paul.
Regards,
Geoff