OMG! This is my problem too, I have windows xp, nvidia 8400 GS, Intel pentium D 2,8 ghz processor. It didn't work in that computer. Apart from that I tried to play it in a windows xp, nvidia 9800 GT, Intel Core Duo 3,2 ghz processor and it didn't work either. What is the problem? I want to play it too, and it happened to me twice. Please answer this post. It happens the same that the guy above is telling.
PS: I don't think that its a CPU problem, both CPUs work fine, and they are good too. I suppose its some unziping trouble or something. Please either fix the problem, or post an answer to it.