This will work in Windows 8.1 or Windows 10.
Boot into WinPE environment and type diskpart
, list disk
, select disk
and list volume
to get the letter of the system drive. Exit diskpart then type C:
or, if the system drive is given another letter, type that instead.
cd c:\windows\system32
ren utilman.exe utilman.exe.bak
ren cmd.exe utilman.exe
Restart into the Windows operating system and press Ctrl-Alt-Del. Click on the icon voice assistant to get CMD window open and then reset the password or enable the local administrator account.
Type net user
to see a list of available user accounts.
Type net user $USERNAME *
(replacing $USERNAME with the desired username), and follow the prompts to set the password for that local user.
Type net user administrator /active:yes
to activate the local Administrator account.
Type net user administrator *
and follow the prompts to set the password for the local Administrator.
If successful, reboot in the WinPE environment to restore the name of the executables.