i know how to fix this...i have done it many times...

this worked on a comp at the hotel we were at the other day...chances are it just wont let you install anything because its a "limated account" , hers what you do...boot in safe mode (press F8 right after the bios cheac) log in as ADMINISTRATOR and create yourself an administrator account or give your old account admin privledges, set a password so the school cant change it back, login to your new account and install away! youl be watching porn on ur laptop in the classroom in no time!

if that dosent work possibley because they thot you would try this and they set a password on the ADMINISTRATOR account...simpley back up all the important stuff to floppies CD or flash stick , and format the drive and re install windows and set everything up the way YOU want it.

and dont forget to set the password hint to say ****OFF!!! when clicked.