http://www.microsoft.com/windowsxp/64bit/default.asp
“If you have a 64-bit ready PC, you now have the option to receive trial software for Windows XP 64-Bit Edition for 64-Bit Extended Systems via CD or download…the pre-release software is time-limited and will expire in 360 days.”
Do you need it?
“Windows XP 64-Bit Edition is designed to address the most demanding needs of technical workstation users who require large amounts of memory and floating point performance in areas such as mechanical design and analysis, digital content creation and scientific and high-performance computing applications.”
I wonder why
“Important: Windows XP 64-Bit Edition for 64-Bit Extended Systems is only compatible with 64-bit AMD Opteron– or Athlon 64-based computers. It cannot be successfully installed on 64-bit Intel Itanium–based systems.”
… No Intel? lol
I you still think you need it:
“The download files are large (approximately 450 megabytes) so the download may take a considerable time to complete. Microsoft recommends only those with broadband, ADSL or other high-speed Internet connections attempt this download.”
Have fun 
