is MY copy of Windows XP Pro 32-bit?

[BobLewiston]

is MY copy of Windows XP Pro 32-bit?
I've got a 32-bit machine (Pentium 4) running Windows XP Pro (version 2002). I understand that there are 32- and 64-bit versions of Windows XP Pro, and that some 64-bit versions of XP Pro will run on 32-bit machines (although I can hardly believe it, and I've also been told that's not true). So how do I know for sure that my copy of XP Pro is 32-bit?

[Fou-Lu]

32-bit.
My specialty is by no means hardware, but best I know a 64bit platform will require the usage of a 64bit architecture. I think what you're hearing is the other way around, 64bit architectures are capable of running 32bit platforms (eg, I have a 64bit architecture in my notebook, but run a 32bit version of windows).
Where's OracleGuy when we need him ;)

[oracleguy]

You are running the 32-bit version for 2 reasons:

1) Most prominently, without a 64-bit processor you cannot run 64-bit code. So you couldn't be running a 64-bit OS. Whoever told you that a 64-bit OS can run on 32-bit only hardware is wrong. You can however run 32-bit code on 64-bit, for example in my 64-bit Windows, I can still run 32-bit applications.

2) When you do run the 64-bit version of XP, it is pretty obvious because all the places that say "Windows XP" also say "x64 Edition". I attached a screenshot from my computer to illustrate this.