Windows 10: How did account "defaultuser0" get created? Why?

I notice that there's an account called "defaultuser0" on my Win 10 computer.
It's not available at the login screen.
It does not show up in the User Accounts control panel.
But it does show up in file/folder permissions. For example, running command line "icacls" on the Desktop folder gives this:
Code: Desktop BUILTIN\AdministratorsOI)(CI)(F) NT AUTHORITY\INTERACTIVEOI)(CI)(RX) NT AUTHORITY\SYSTEMOI)(CI)(F) BRUCEDELL\defaultuser0OI)(CI)(D,DC) BRUCEDELL\userAOI)(CI)(F) BRUCEDELL\userBOI)(CI)(F) BRUCEDELL\userAOI)(CI)(IO)(DE,DC)[/quote] What's up with this rogue/phantom account?

:)

 

How to fix " Unknown Artist " ?

My favourite is MP3Tag, google it.

 

Bought a pc with widows 10 - cant get in.

I recommend you do your own Factory Restore in order to get the equivalent of a brand new PC, without any flaws or account problems.

 

Defaultuser0 is a system user profile used when Windows is setting up, before any user accounts have been created. It should and usually does disappear after first reboot after installation. If the profile folder remains in Users folder, it's safe to manually delete it.

 

You can also delete the user with net user defaultuser0 /delete and delete from HKLM\Software\Microsoft\Windows NT\CurrentVersion\ProfileList\

There is a long thread (more than a year) about this bug in the link below and it seems it isn't resolved yet. I certainly still get it on clean install - no particular pattern except some machines do it more often than others.

created on clean install of Anniversary Update - Microsoft Community

It doesn't really matter as you can't use defaultuser0 credentials anyway but it is certainly sloppy.

 

It is most definitely not a bug.

Windows 10 is fully functional when OOBE (Windows Welcome) starts after installation. Because built-in admin account is disabled by default, and at start of OOBE user has not yet created the initial user profile, a temporary user profile is needed for OOBE to work. That temporary profile is defaultuser0.

As I mentioned, in a normal, default clean install it will be automatically removed after first restart after the installation has finished.

You most definitely can use it. In OOBE, before you have created the first local user account, Windows 10 signs you in with defaultuser0 account allowing full access to Windows. You can install programs, surf the net, change settings, anything you want to while being signed in with defaultuser0 account, never creating any other user accounts.

In this post you can see a presentation that explains it a bit more: Tips and tricks - You saw it first on TenForums! Solved - Page 3 - Windows 10 Forums

I repeat: defaultuser0 is, although temporary, an important system account. It is absolutely not a bug nor is it created because of a bug.

 

The bug is it isn't always deleted. If it is temporary profile it should be deleted (not only from C:\Users but from net user, registry etc) after your clean install completes. If it was meant to remain it would always remain but clearly this isn't the case.

No-one know why it isn't always deleted although there is much speculation.

 

I've deleted the defaultuser0 account, following instructions found here and elsewhere.

Thanks for the help.

 

Out of interest, what did you do?

I delete C:\Users\defaultuser0 directory and run net user defaultuser0 /delete

I'm not sure whether deleting all the other stuff is required.

It would be certainly interesting if MS came up with an answer but apart from a vague commitment to it being fixed in April 2017 release (it was not) we heard nothing.

 

I imaged a classroom of 30 computers with the same image. Two of the computers had the defaultuser0 come up on the sign in screen. The others did not. Deleting the user did not work. The only thing that did was imaging them again.