Link: Snow Transformation Pack 1.0 Released |

Snow Transformation Pack will transform your entire user interface to Mac OS X Snow Leopard, including Snow Leopard Welcome Screen, Visual Style, Icons, Wallpapers, Sounds, Dock and much more.
This tool is compatible on the all the versions of Windows as it has been checked with Windows 7 64-bit Ultimate edition.
I haven't tried this myself [not that knowledgeable on Mac] but posted here in case it proves to be of use to others.