Delete Files And Installs On Shutdown?

a university I attend on Saturdays has a setup on their computers that deletes all files that were added to the computer (as in anywhere) and any new installs, but without deleting stuff the university wants to keep, like Firefox, UConnect, Adobe Flash, etc. And it has an exception on the My Documents folder that things added to the My Documents folder will be kept on there for 14 days, then automatically deleted. And the computer deletes all this stuff once it shuts down. When you turn it back on, nothing of the stuff added is there and looks like a fresh new install of Windows 7 with Firefox and all that sort of stuff kept.I've been googling and binging for how to do this, but no successNot sure if it's a program or a script.Just want to delete everything besides stuff I want to keep like Firefox, Microsoft Security Essentials, Adobe Flash, Shockwave, etc (and possibly make an exception for the My Documents folder as well)