DirectX Strange problem

[amplifyed]

Well, I got my hands on a copy of RCT Platinum. But then, I find it can't run without "DirectX," but when I try to install it, it says "An Error occurred... (And it has this ridiculously long link to a website in the error window, which makes no sense.) And it refuses to install. Anyone know how to solve it? I'm running Windows XP on a mac using bootcamp, and I don't have internet connection on my windows desktop, if that makes any difference. Thanks a bunch in advance!