Have a 64 bit CPU?

[JimmyTango Profile]

http://www.microsoft.com/windowsxp/64bit/evaluation/upgrade.mspx

Microsoft is offering a free Windows XP Professional x64 Edition Customer Preview Program.

I wouldn't use this as my main OS. Start a second partition on your HD or install it on a second HD for dual boot.

[LordShard]

Important: Windows XP Professional x64 Edition cannot be successfully installed on 64-bit Intel Itanium–based systems.

[Agent-Commando]

Important: Windows XP Professional 64-Bit Edition may include numerous security flaws and bugs. We told you we'd screw you over always! Micro$oft pwns j00!