Excuse me for asking... but if you "have a laptop which has only 1 user account", then that user-account IS the computers Administrators account..
Exactly what do you think happens if you remove that account?
How would removing this account help you to create an NEW account in the same computer?? (Hint! You need an administrative account for that!)
This is the type of problems you get when you install Windows "the Microsoft way", that is to "sign in with YOUR Microsoft account" at the end of the setup! The first account created is, like everyone knows, made to be the computers ADMINISTRATORS ACCOUNT (Member of the Admin group)..
Your account will the only Administrative account in the computer, and when stuff like this happens... You have locked yourself out from your own computer... especially when it's a Microsoft account (that password reset software's CAN NOT CHANGE THE PASSWORD ON...
Luckily for anyone in your situation there is a guide that shows how to do away with these faults when you perform the reinstallation of Windows that your probable is forced to perform... Please check out the: Link Removed for more help!
That way no one must end up in this situation. (caused by Microsoft idiocy to fool everyone to sign in with their Microsoft account instead of making a separate Admin-account BEFORE you create your own Standard user account)
(Pardon me if I misunderstood anything)