Some newer systems will not work with XP due to my experience in trying it. Do you have all the necessary equipment to do this? If so you could attempt it, otherwise if you have to buy the software i would probably go with Win 7.. but if you post what setup you are looking to install XP someone should give you a better answer.
I run XP on an i5, so I can tell you that it works. The choice of motherboard could be the issue, if some more recent motherboards require drivers not in the XP distribution.
I would recommend using an XP disc with SP3 already applied (if you don't have one, look up slipstreaming). If the install is missing drivers, you might try transferring drivers from the motherboard CD to a USB stick and using the F6 mechanism. Ask again if you hit driver problems.
But the CPU itself is compatible with XP. Good luck.
Joke answer: "No, you can't. You have to install it on a hard drive."