Thanks for the reply. I checked my Services page and could see my subscription in there. There was a file sitting in the install section which suggested I needed to download 365 again - not sure why. Anyhow, I've done that and restarted my laptop.

When I now attempt to open an existing file in Excel I am hitting a different problem. I'm no longer stuck in this previously mentioned interminable loop, however, I cannot edit my file as the following warning message appears: 'ENABLE EDITING: To edit files in this free version of Excel, they must be saved to OneDrive'

-- I don't understand this as I don't have a free version of Excel!

Alongside that error message is a 'Get Started' button which then asks me to save to OneDrive. However, when entering in my hotmail email address to sign in nothing happens and I'm sent back to Excel again with the same enable editing issue.

Also at the top of my Excel screen in the task bar are two buttons to either 'Sign In' or 'Buy Microsoft 365'.

It just seems like the installation of 365 isn't being recognised whatsoever!

Help!!