Windows Server 2003 x64/ Windows XP Professional x64http://blogs.msdn.com/b/nickmac/archive/2004/08/30/windows-server-2003-x64-windows-xp-professional-x64.aspxWe’ve just announced the beta customer preview program for Windows Server 2003 x64 and Windows XP Professional x64. This supports the new hybrid 32/64-bit architecture that AMD released a while ago (Opteron), and Intel just released (Intel Xeon with Intelen-NZTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)