PLEASE HELP ME !!!THANKS YOU VERY MUCH!!!!

I bought a dell e521 desktop with Vista home system , I already found one of my important programs will not run on Vista.
Could you tell me how to have windows XP put on the machine instead or Vista?

I guess that the computer should be FROMATED, AND THEN INSTALLED WINDOWS XP. I DO NOT KNOW IT RIGHT OR NOT?跟以前从装系统一样吗？


PLEASE HELP ME !!!

THANKS YOU VERY MUCH!!!!