I have DAT achiever. It only works on 1 computer after login, using your hardware as an identifier. I had Topscore which works the same way, then my HD crashed. I had to complain to the company forever and show them my reciept of buying a a new HD before they finally gave me a new key. Just go buy the thing. - It was much much harder than the real thing. I was getting way low scores on it, 12,13,14, and got average 18 on the real one. It was a good study tool though, i'm glad i had it.