How to Run Windows Commands Outside the OS?

I'm trying to make a password reset utility and I think that the easiest way is to run the net user command on a specified user. I am thinking about making an iso that asks you to select a user, and then runs a command for windows to reset it. Does anyone know how i could do this? If this would not work, can anyone give some insight as to how password reset utilities work, or how the command itself works, so i can do it manually.

Thanks.