Hello Bridge and welcome to the forum.
If this is a Windows 10 Pro machine you can use
lusrmgr.msc
To control, edit, enable, etc., user accounts
IF not then you are left with either using the less robust Users Accounts manager in the Control Panel (manage another account)
OR you can try it from the command line.
Right click the Start Button and choose Command Prompt (Admin) and in the Command Prompt window type
net user
hit enter
That should produce a list of users on your computer.
IF you see the problem user name (account) then you can type
net user UserName /active:no (there is a space between the end of the username and the / )
hit enter
That should disable the account and it should no longer be presented on the login screen
WARNING: Make absolutely sure that you have a or multiple other accounts available to your with Admin rights (members of the local administrator's group) before doing this.