I just bought the game today. The demo didn't work for some reason though I never got the answer bc the moderators closed my thread. I'm guessing the demo didnt work for the same reason that the game isn't installing (what's the chance that both aren't working for different reasons?). Here's some information:
1) My computer is only 6 months old, I have 4GB ram, GEforce 9100, plenty of hardrive space, vista, and I have never had any problems with any game (including many old games) on it.
2) I have never had Steam before on this current computer, though I do have an account which wasn't active for over 1 year until I logged on to play the ETW demo.
3) When I press install, a window comes up that says "Installing system components" and then a new window comes up that says "Failed to run install script"
4) Every other TW game works on this computer.
I'm guessing the problem is with vista or steam. I'm hoping someone can find a solution because calling either microsoft or valve would be a pain in the ass. Please help!