Popular software put out by Smartstuff Solutions (smartstuff.com) used on computers in US public schools. It works on Windows and MacOS, and disables certain menu items and functions, to stop students from accidentally (or purposefully) deleting files or formatting the entire machine. However, if you're a teacher assistant and you're trying to get your teacher's computer to work, or the computer won't let you save your report because it doesn't allow file saving, the software can be really annoying.
Not to fear, there are plenty of ways to circumvent the software. On windows machines, it's simply a matter of holding ctrl or hitting F8 while the computer is starting up to get to a DOS prompt. From their you just need to remove line requesting the foolproof device driver from C:\windows\system.ini, and in C:\config.sys (and C:\windows\config.sys in some cases). If for some reason this doesn't work, (depends on foolproof version), from the DOS prompt just rename the entire foolproof folder to something different. Then when windows boots up it'll give an error, but ignore it for now. You've made it through, but you want to get rid of that nasty error so your teacher doesn't suspect right? Rename the folder back from windows, and then uninstall the software in the Add/Remove Programs Control Panel. Finished.
On MacOS, simply hit the shortcut key during startup to disable extensions, and then once booted remove the foolproof extension.
MacOS X not covered here because it isn't out yet, and niether is a version of foolproof for it. Also, not sure how to circumvent foolproof in Win2k, but most school systems aren't running it. /msg Nanosecond if you know how.