LinuxMCE is a free, open source add-on to Ubuntu, so you need to install Ubuntu first.
you can download Ubuntu from here: http://www.ubuntu.com/getubuntu
you can install Ubuntu and still keep your current windows OS
LinuxMCE is the only solution seamlessly combining:
1. media & entertainment with a server for music, movies and tv shows, plus a PVR and DVD Player,
2. a home automation system to control everything in the home with touch-screen tablet and Bluetooth mobile phone controllers,
3. a phone system with video conferencing,
4. a security system that feeds you live video on your mobile phone when something happens, and lets you speak to visitors through your stereos, and
5. a home PC solution.
i think it should meet your needs.