Make sure that you have returned everything to where they were as they were. If step 4 isn't possible then once step 5 is done the quickly create and administrator account on every individual machine that you may most possibly use and then execute command : "net localgroup administrator (username) /delete" (this should all happen between 30 - 90 sec) Then after a minute or so if you did everything right every computer that is logged on with that user will restart, then you will see that the user is admin. Warning this step may require some criminal intuition! Now wait for the teacher to leave to the bathroom or get coffee or whatever, then get the bat file from earlier and go and execute it on his machine provided that he has logged on as administrator.
Make sure that you have a lets say weak IT or CAT teacher(untrained) at school. open CMD if possible on a random computer connected to the domain/network and type "net user" if you see the username you want to change, then smile because life just got easy. so go to notepad and type "net localgroup administrator (username) /add" then save the file as. Make sure that you know the name and password and domain of the user you want to extend to admin.
#CMD HACKING INTO LOCAL COMPUTERS HOW TO#
so now I will give you an alternative on how to do this. so the problem is that you require some extended privileges in order to create an admin account. I looked at this thread (unable to display due to website rules) and I see that there is a problem here.