Problem logging out / unable to un/re-install icloud

When trying to sign out of icloud to input a new user ID, we're not able to do so.

When clicking sign out an error message is received - error code 2343

Further to this - I'm unable to uninstall icloud desktop via the control panel, it get's so far and then fails & rolls back.

There is also another error message listed below relating to Outlook - how is this anything to do with outlook?

I'm just trying to update the user ID details, but so far have been unable to do so - help please! Thank you...