Yes, it is possible to recover from the scary event that you forgot your Windows 10 password and you are locked out! This method has been fully tested, via my own Dell Laptop, on the latest build of Windows 10 (currently at v1903 at this time).
The Basics: Windows 10 has two types of user accounts: 1) Local Accounts and 2) Microsoft Accounts. A Local User account exist only on one single physical device (computer) and a Microsoft account becomes global and is shared with other devices you may have.
Reset a Windows 10 Microsoft account password
For this type of account, you reset the password reset at the Windows sign-in screen by selecting “I forgot my password”.
You will see a Recover your account prompt where you can enter the username (email, phone or Skype) of the account you wish to reset the password for. You will be asked to Verify your identity to enter a security verification code that will be sent by either a linked email or mobile that is part of your account. Once your identity is verified, you will asked to enter a new password.
Reset a Windows 10 Local account password
First you will need create a bootable Windows 10 DVD or Flash Drive. Download the Microsoft Media Creation Tool to create a bootable installation media on your choice of either a flash drive (at least 6Gb) or a dual-layer 8.5Gb DVD.
Boot from the bootable media created above.
Choose “Repair your computer” during the Windows 10 Setup & Installation.
Select Troubleshoot > Command Prompt (see images).
Now in the command prompt window select the correct drive letter that Windows is installed on (typically C: or D:) and switch to the system32 directory; e.g. cd C:\windows\system32 or cd D:\windows\system32 (check by doing a dir /a on which ever drive has Windows).
Type rename utilman.exe utilman.bak inside the correct \windows\system32 directory.
Type copy cmd.exe utilman.exe
cd C:\windows\system32 rename utilman.exe utilman.bak copy cmd.exe utilman.exe
Restart the computer and boot your normal Windows 10.
Hold down the Shift key and then click on the Power button to select Restart.
After the Restart select Troubleshoot.
Select Advanced options
Select Startup Settings
Select Restart on the right side of the Startup Settings page.
When the Startup Settings screen appears after the Restart, select option 8) Disable early launch anti-malware protection (enter 8 on the keyboard).
Click on the Ease of Access icon on the next start on the login screen which will now open a privileged command prompt window to open.
Now a command prompt windows opens. Ignore any error message you see in the command window!
In the command windows type net user to display the names of all user accounts known to Windows.
Use the command net user [username] [password] to change the password of the account, e.g. net user “Peter Bowey” qwerty3456 to change the password of the user martin to qwerty3456.
Now exit the command window and log in using the account name above that you changed the password for. Windows will now accept and use the new password (qwerty3456).
net user --------------------------------------------------------------------- Administrator DefaultAccount Guest Peter Bowey WDAGUtilitySccount The command completed successfully. net user "Peter Bowey" qwerty3456
Success, you are now able to use Windows 10.
Restoring the Windows file changes
Once you have successfully performed a log in to Windows you need to again boot from the previous DVD / flash drive media and choose Choose “Repair your computer“.
Select Troubleshoot > Command Prompt (see previous images).
Now, as before, in the command prompt window select the correct drive letter that Windows is installed on (typically C: or D:) and switch to the system32 directory; e.g. cd C:\windows\system32 or cd D:\windows\system32 (check by doing a dir /a on which ever drive has Windows).
Type del utilman.exe inside the correct \windows\system32 directory (this removes what we placed earlier).
Type ren utilman.bak utilman.exe (this restores the original utilman.exe).
cd C:\windows\system32 del utilman.exe ren utilman.bak utilman.exe
Restart the computer and boot your normal Windows 10. That’s it, you have now successfully recovered from a forgotten password scenario.