It were around 1997~1998, I was on middle school. It was a technical course, so we had programing languages classes, IT etc.

The IT guy of our computer lab had been replaced and the new one had blocked completely the access on the computers. We had to make everything on floppy disks, because he didn't trusted us to use the local hard disk. Our class asked him to remove some of the restrictions, but he just ignored us. Nobody liked that guy. Not us, not the teachers, not the trainees at the lab.

Someday a friend and me arrived a little bit early at the school. We gone to the lab and another friend that was a trainee on the lab (that is registered here, on DevRant) allowed us to come inside. We had already memorized all the commands. We crawled in the dark lab to the server. Put a ms dos 5.3 boot disk with a program to open ntfs partitions and without turn on the computer monitor, we booted the server.

At that time, Windows stored all passwords in an encrypted file. We knew the exact path and copied the file into the floppy disk.

To avoid any problems with the floppy disk, we asked the director of the school to get out just to get a homework we theorically forgot at our friends house that was on the same block at school. We were not lying at all. He really lived there and he had the best computer of us.

The decrypt program stayed running for one week until it finds the password we did want: the root.

We came back to the lab at the class. Logged in with the root account. We just created another account with a generic name but the same privileges as root. First, we looked for any hidden backup at network and deleted. Second, we were lucky: all the computers of the school were on the same network. If you were the admin, you could connect anywhere. So we connected to a "finance" computer that was really the finances and we could get lists of all the students with debits, who had any discount etc. We copied it to us case we were discovered and had to use anything to bargain.

Now the fun part: we removed the privileges of all accounts that were higher than the trainee accounts. They had no access to hard disks anymore. They had just the students privileges now.

After that, we changed the root password. Neither we knew it. And last, but not least, we changed the students login, giving them trainee privileges.

We just deleted our account with root powers, logged in as student and pretended everything was normal.

End of class, we went home. Next day, the lab was closed. The entire school (that was school, mid school and college at the same place) was frozen. Classes were normal, but nothing more worked. Library, finances, labs, nothing. They had no access anymore.

We celebrated it as it were new years eve. One of our teachers came to us saying congratulations, as he knew it had been us. We answered with a "I don't know what are you talking about". He laughed and gone to his class.

We really have fun remembering this "adventure". :)

PS: the admin formatted all the servers to fix the mess. They had plenty of servers.