Stop configuring Firefox for each stinking user. Create the file mozilla.cfg and edit all.js, and that's it: Firefox will be set up for the DOE's proxy settings for each and every logon. The trick works for Windows, Mac OS X and Linux.
Psshutdown.exe is a free utility from Microsoft that allows you to shut down computers remotely. The hour you take to set it up will easily save your school $2000 a year on its electric bill. It will also reduce carbon emissions in a big way.
XP's group policies let you impose the proxy server used by IE upon all logons. GPs do a whole lot more, too, like lock in the home page, wallpaper and screen saver.
A few links you might need at school.