Previous versions of OS X server were stadandalone installations that could be installed on any machine and run as a separate operating system. However, Lion Server is a different story as it is now an app within OS X itself. In short, how would I be able to run OS X Lion Server on a Windows installation or on Windows hardware?
You can't. Apps compiled for OS X cannot be run on Windows, and likewise, Windows programs don't run on OS X. If you want to use Lion Server, you will need to run it from OS X on Apple hardware.