You can do the same thing without using a boot drive at all.

  * Press F11 while booting
  * open cmd in the rescue menu
  * navigate to windows system32 folder
  * rename sethc.exe to sethc.exe.backup
  * copy cmd.exe to sethc.exe
  * reboot and press at login 5 times shift
  * add admin user
  * profit

Thing that is missing is password edit of online only accounts or convert to local account