You might be surprised. go give it a try.
Windows Steady State works on Windows XP and Vista. It will not work on 7. Steady State is free at microsoft.
Faronics Deep Freeze works on everything. Deep Freeze is $40 but there is a 30 day fully functional free trial.
As I said in a seperate post, We had 15,000 people in our internet cafe in 5 months. not a single virus or spyware infection that lasted past a reboot. We threw a lot of junk at it testing it too. not once in over 40,000 running hours was there an infection.
Set up a test machine and beat the hell out of it.
If our medical industry worked like this, we would have a lot more cures for things and a whole lot less pills they are pimping on us all the time.