As I am sure you are not trying to STEAL Windows XP, what you need to do is determine why you want it and then get it through the appropriate channels.
If you want it for testing and evaluation, your TechNet Plus Direct subscription has a download for it.
If you want it for development purposes, your MSDN subscription has a download for it.
If you want it for your business, I BELIEVE you can download it from the Microsoft eopen web site, provided you have a volume license for Windows XP, Vista Business or Enterprise, or Windows 7 Pro or Enterprise.
Otherwise, you CANNOT legally download it.