Home premium and Ultimate.
Windows media center is available with Windows Operating systems - Vista, Windows XP Media Center Edition, and all editions of Windows 7 except for Home and Starter. If its a Vista OS may be you can call it a vista media center, so you need your computer to have Windows Vista OS.
Home and Media Center editions.
Windows media center and windows tablet PC editions are available only on supported hardware devices and its not available as standalone products
Windows Media Center acts as a kind of central gathering for all of the media programs that you have on your computer, such as Windows Media Player.
Windows Media Center Extender allow devices which are running a windows operating system to connect or link up over a network connection. Files can be viewed or watched over the network.
Windows Media Center isn't part of Windows XP Professional. It was only available in Windows XP Media Center Edition.
Windows Media Player, Windows Media Center, Windows Media Smart? Difficult to answer when your question can apply to several different softwares.
there is no such app for windows media player, but there is app for windows media center and it is not free.
http://blogs.msdn.com/astebner/pages/customizing-the-windows-media-center-start-menu-in-windows-vista.aspx
Windows Media Center
Windows Media Center can be downloaded from the Microsoft website. One will also find on the Microsoft site advice on how to set up and use the Media Center.
The executable file for Windows Media Center (MCE) is called ehshell.exe and is located in the Windows > ehomedirectory.