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I'm not sure what you are asking. If you are asking if you can use a Magic Trackpad or trackpad in Windows 7, you can.
If you want to install Windows on your Mac, you just have to install the Windows support software. If you are using Lion or Mountain Lion, Boot Camp Assistant will ask you to download it, and you have to install it in Windows. If you are using Snow Leopard or Leopard, it comes with the Snow Leopard or Leopard DVD.
If you are referring to the Magic Trackpad on a PC, there are how-to's in Internet about how to use it in Windows in a PC