+1
Reboot Restore RX - I've used that many times. Seems as though the dentists around here love to screw up their PC's so I install RX prior to working on it just in case things go wrong. I can always restart with exactly what state the machine was in prior to working on it. Would NOT recommend it for schools however, see below.
Did this a while back for a school. Only had 3 PC's in the library so was quite easy to do and worked pretty good. Also have done this for a couple nursing homes as well. This was the video I followed back then.