netplwiz not updating account username

Question

Currently when I start my Windows 10 desktop I get a failed auto-login (Incorrect user name or password...) - this is because it is trying to use an incorrect username. I can then login by entering the correct details, or by switching to using PIN.

When I try to use netplwiz to change my account user name I get "The user name for <User> could not be changed"

I have tried creating another Administrator, logging in as that user and then trying to update the user name for the main account but I get the same error.

I have "Require Windows Hello sign-in for Microsoft accounts" disabled, and "Require Sign-in" disabled in "Sign-In Options"

I have "Users must enter a user name and password to use this computer" disabled in netplwiz

I have never updated my username previously, and did not consciously ever set the username to the incorrect value (the incorrect username is a truncated version of the real <name>@outlook.com one). The machine was recently re-built and no other accounts have ever been used on it apart from the two described here.

How can I correct my username?

Answer 1

When using Netplwiz, all it does is make registry changes. Since all you want to do is alter the login information, the easiest method here is to edit the registry directly.

You will want to navigate to the following path: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon

Alter the settings for DefaultUsername and DefaultPassword according to your new settings.

If these contain anything invalid, such as a typo, you will get a logon screen upon subsequent boots until the right information is stored.

See also: external documentation

That said, if you have chosen to convert your local user to a microsoft account (for example, you clicked yes when got this question asked in the Windows Store) your username does change, so either set your username to the email address of your microsoft account or go into settings, accounts and convert your microsoft account back into a local account. When converting back, chances are high that you don't have to make any registry changes etc, and it will work like normal again.