Alright this is sort of a sequal to Stephen's tutorial, but also has several more fun bypasses...
If cmd is blocked, and you cannot get into it because admin has blocked access to cmd, in every way/shape/form there is one way that will ALWAYS work, but you need a friend who trusts you.
Step 1: Open up notepad, then type "runas /user

ERVERNAME\USERNAME cmd"
Servername is the name of the server you logonto at school, mine's "EDC2021"
after you do this save it as a .txt file, then rename the .txt to .bat and double-click, it will now ask for that user's password, type it in and voila, working cmd with more bypasses built in.
should you have access disabled to alot fo things including C:, use this method to bypass the blocks and access these areas.
Want to get into the server to change what happens on logon, or more?
simply right-click->shotcut and type in "\\SERVERNAME" then hit next, then finish, double-click your shortcut and you have free reign of the server, and if it's like my school, every computer in the school.
Will add more, using my vast knowledge of school bypasses (4 years of practice >

, and a school with EXTREMELY tight security because of me.) just ask what you need to know.