Windows 7 PC Safeguard.
Windows 7 PC Safeguard is another new Windows 7 feature that recently came to light. The feature can be enabled on Windows 7 standard user accounts and has the effect that changes to the system will only be temporary. Microsoft is offering a similar feature in the form of Windows SteadyState for computers running Windows XP and Windows Vista. It seems that they have taken some time to evaluate Microsoft software programs and made the decision to integrate quite a few into Windows 7.
PC Safeguard does not provide many configuration options yet but it could be that Microsoft has plans to integrate some of the more advanced SteadyState features such as blacklisting applications to the software program before they release Windows 7. The only available option is to provide some disk space for data storage. The restricted user will be reminded after login that the changes that he makes to the operating system will be undone after logging off. Read more at the source