Managing a computer that is used by more than one person can become a tedious job, especially if users have access it without too much knowledge just tear up everything - installing applications, accessing malicious sites that sends viruses to our computer, etc ..Windows SteadyState is free application from Microsoft that allows us to manage these computers and return them to their "original state". This application is the successor of Shared Computer Toolkit, a tool that already exists, to which added several new options.
This application allows us to manage various user profiles, changing its configuration to limits accessing certain options, such as the control panel or management network, etc.
Once you've made these blockades will facilitate computer back to the original state, by simply restarting, but we can also define how long the changes will be kept on disk. For example, a computer room could be reset every time you have new students.
Windows SteadyState work with Windows XP with SP2 installed and download and use are free.(source)