The program you are looking for is Deepfreeze br Faronics. Google for it. When frozen a user can load, maul or obliterate the OS to his/her satisfaction and a reboot puts everything back to where it was before the mauling. Be careful as Deepfreeze is very hard on data, email messages etc. Remember that when a system is frozen everything is transparent and will be lost on the next reboot. I use this program in a classroom environment and it works well. It is dynamite on a home system where you like to preserve your data for some time.