Whats the difference between.....

[Guest]

Whats the difference between Windows XP Professional and Windows XP
Professional X64? Is this a upgrade or a whole different Windows Program?

 

[ms_dude]

same prog but different hardware ... 64 bit that is ...

 

[Kyuzo]

XP Professional x64:
http://www.microsoft.com/windowsxp/using/64bit/russel_x64faq.mspx

 

[Ken Blake, MVP]

Whats the difference between Windows XP Professional and Windows XP
Professional X64? Is this a upgrade or a whole different Windows
Program?

The X64 version is not an upgrade but a different version, designed to run
on a 64-bit computer. Unless you have such a 64-bit computer, it's useless
to you. Most people have 32-bit computers, although 64-bit ones are becoming
more popular.