Windows 10: Can't sign into user account windows 10

My brother own HP Gaming Pavilion - 15-dk0045tx which recently gotBIOS update and he completed the process of the BIOS update but somehow his user account is got corrupted and shows this error message everytime he boot the laptop




i was trying to find some solution on internet when i found this video i am giving a brief on what happen in video and what i did wrong

optional to watchhttps://www.youtube.com/watch?v=TFYW9AxRCkw optional to read

-press win+r

-type regedit

-go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

-find profileimagepath where the path is on temp location

-modify the path to your user name stored in C:\Users

-take the backup of your user account

-delete the .bak file

-reboot

"i did all he said but the most important step to take backup i forget it and **** up there"

now when i am checking the C:\Users i am not able to find the username file which mean it is deleted now what should i do

:)

 

Strange Windows 10 User Account issue.

Unfortunately I had done those steps numerous reboots, it just, reappears for no good reason. The base account isn't even a Microsoft account, it's a local account.

I haven't quite tried the built in administrator account on W10, but so far in my experience on my own computer, the built in account seemed to have absolutely no more control than I did on my own.

It's just strange, I go in, it warns me twice about deleting the account, then it's gone. Reboot, and it's back?

EDIT: Just to specify, both command line and Netplwiz both say only HIS account exists on the computer, it doesn't list this rogue account. This is what I meant in my first post about the fact that even Windows doesn't seem to believe it exists, HALF the time. *Frown

 

Windows 10 Tweaks

As you may already know, Windows 10 (as well as Windows 8) allow you to log in with a valid Microsoft account, instead of creating a local account that only works on your machine. However, you may prefer to keep a local account for privacy reasons. If you do, though, some Windows 10 features—like Cortana—may not work. Despite the default behavior, the Windows 10 Store is not one of them. You can still log in to your Microsoft account for just the Store without switching to a full Microsoft account. The process, however, is not terribly obvious. To do so, follow these steps:

• Launch the Store from your Start menu.
• Click the user icon next to the search box.
• Click “Sign-in” from the menu that appears.
• Choose “Microsoft account” and log in like normal.
• When the “Make it yours” box appears do not enter your password. Instead, click “Sign in to just this app instead.”

from Lifehacker

 

Strange Windows 10 User Account issue.

Look at this thread,How to Delete a User Account in Windows 10, it may help. You can try the various methods.
Make sure you are using an administrative account when removing the account or log on using the Administrator's account.

Or, if you are patient and know what you are doing, manually remove it.

Either way, Goodluck.