Stuart Harrison

Ah, lovely. That's got it, thank you!!

I'm having this problem too. I don't actually remeber signing into any Microsoft account, and have no way of finding out what account I used. I think this is more a UX issue than anything. If there was an easy way of seeing what Microsoft account was associated with an account and being able to disassociate your MS account from your Switch account at a push of a button, this would solve the having to delete all your data problem and provide an easier way of starting with a clean slate without losing all your saved worlds.