There are two version of windows XP.
32 bit-->> X32
Will work only both 32 bit and 64 bit processor
64 bit-->> X64
will work only on 64bit processor
64 bit XP is advance version of windows 32 bit.It is fast, better appearance, better 3d view.
And 64 bit applications will run only on windows 64 bit editions.
How to know Windows XP is 32 bit & 64 bit
Start-->>right click my computer-->>properties-->>General
If operating system is written as:
Microsoft Windows XP Professional Version< Year>
Than it is 32 bit XP.
And
If operating system is written as:
Microsoft Windows XP Professional x64 Edition Version < Year>
Than it is 64 bit XP.