I had to reset the password on a Win10 machine recently and found out they closed the loophole where you could boot with any live boot disc such as a Linux distro or the Win10 setup disc then rename the utilman.exe to something like utilman.bak then copy cmd.exe as utilman.exe and you could run command prompt from the login screen with system privileges so you could create a new admin user. That sucked but I found a boot disk that just wipes all user passwords. However, changing passwords this way loses the key for all encrypted files encrypted with the unknown/forgotten password.