I’ve tried to do many things with the school computers, some of which involved administrator access as a requirement. This method isn’t guaranteed to work, and many higher-tech schools have blocked it by now, by I suggest attempting it anyway. Here are the instructions:

  1. Open Command Prompt (see here).
  2. Type ‘net localgroup’.
  3. Have a look through the list. One of these should contain the word ‘admin’ or ‘administrator’.
  4. Now type ‘net localgroup thegroupsname /add’.
  5. If this doesn’t work, try ‘net localgroup thegroupsname /add yourusername somerandompassword’.
  6. If this doesn’t work, your school have blocked the command entirely.
A very important note on this is that if they indeed blocked it, every attempt will be recorded, and likely looked over by your school’s technicians.