1) As another person once said, did your computer cost more then a new car?
2) Did you mortgage your house to buy it?
3) Did you specifically place a special order for 64 bit?
If you had it, you would know.
If you have to ask, you do not have it.
If you "must" check for yourself, try SiSoftSandra.
BTW, 64 bit starts with the processor.
You would have to have a 64 bit processor
and MOBO before you could even try to
install the 64 bit version of XP.