go with what
ShawnD1 recommended.
Knoppix is a great utility...it's Linux on a "live cd" meaning it runs entirely from the cd-rom drive, using the available system memory (the more the better) as a virtual hard drive.
what you do is first download (or buy) the Knoppix software, and burn it to a cd. the Knoppix operating system is a version of Linux, which is about 700mb compressed, so it fits on one CD-R cd.
next, pop it into your school puter's cd-rom drive, and restart the computer. if it has a constant ethernet connection, you will be online in less than 4 minutes. it won't boot as fast as a traditional operating system, because it runs entirely off the cd-rom and uses the available system memory.
you'll be able to bypass any windoze software blocks on that puter, and use the hardware with little or no problems. the cd comes loaded with Open Office, a M$ Office replacement, and two different GUI interfaces, Gnome and KDE.
see
Knoppix on TechIMO Linux forum search for help on how to's, etc.
when you're ready to shut down, or log off, all you have to do is "log off" and the cd ejects itself. hit "enter" and the computer shuts down. you may want to just hit the power button to restart the puter for the next person.
you might want to try "peanut linux" on your pen drive if you don't want to use a cd-rom...here is an
excellent article on Peanut Linux.
good luck on whatever course of action you choose...but remember; disabling the controls your admin enacted for your school is NOT what you should do. instead, experiment with Linux and creative ways to learn about computers, and don't use what you know for destructive purposes.
when in doubt, don't do it! Experiment on your puter at home first, so when you get to your computer lab, you'll be quick, efficient, and everyone'll see that you're a pro!

have fun, linux is really nifty
~Branson
~Branson