Windows XP Media Center Edition 2004 ("Harmony", September 2003) Windows XP Service Pack 2 upgrades earlier versions of MCE to this one. Windows XP Media Center Edition 2005 ("Symphony", October 2004) is the first edition of MCE available to non-Tier 1 system builders. Among other things it includes support for Media Center Extenders, and CD ...

Microsoft Windows XP Professional x64 Edition, released on April 25, 2005, is an edition of Windows XP for x86-64 personal computers. It is designed to use the expanded 64-bit memory address space provided by the x86-64 architecture.