We are experiencing the same problem in our lab on our vista computer. We seem to have maybe gotten further than item 150 (though I am not sure exactly how many items were complete), however, we experience the same purple freezing screen. If we do the exit code immediately (ctrl,alt,right arrow) we can save the data we have accumulated so far, but if other buttons are pressed, we have to ctrl, alt, delete out and lose all data. The funny thing is that we are experiencing the same problem with a machine that came with vista, but was later switched to XP??? Is it something about the vista computers and not necessarily the OS itself???