When I was in highschool I got in trouble for using a floppy modified to contain USB drivers to boot into DOS, copy the SAM and SYSTEM files from XP machines and use SAMinside to crack them, gaining the Admin password. I just wanted to torrent in school and get to sites they had blocked, besides being a restless rebel that was bored and sick of control. I confessed to the incident when I was caught and even apologized to the IT administrator on my own accord. I was suspended from computer access at school for a week. Don't stress, be a man and fess up. If you get an unfair punishment take it as a lesson learned and move on.