Cortana In A Loop?

I have successfully set up Cortana on two user accounts, however when I now try to set Cortana up on a user account I get stuck in a loop. I get the screen up that says "One last thing sign in with Microsoft account. Enter old password one last time". I do this then I am shown "That way, I can keep track of what you want me to know".Then I get " Welcome back lets pick up where we left off".

Then it just goes round in a never ending loop. I have created new user accounts to see if the problem was with existing accounts, but still no joy.Looking for answers to the problem on the internet, I have seen it suggested that something can be done by editing the registry, but I do not feel confident to mess about with the registry.I had thought resetting the computer, but am worried that I may not get Cortana to work on any accounts (it is working on two accounts at the moment)