Here is a very nice piece of software. When you get tired of being oh so good to your computer and feel like playing with some dangerous download, or am letting someone use the computer for a while and you know their going to screw the computer up, Windows Steady State is here. What I find very odd…is that its released free by Microsoft, without any fanfare.
But heh, it works and its free. It makes a cache file which includes all the system changes, when you revert, it simply clears the cache.
Check it out: Microsoft Windows SteadState