Download cpuz from http://cpuid.com/
after u downloaded it, open the program(no install is
needed)
then click on main boaard, check the manufacturer and
chipset
then go to the manufacturer website to find the model
actaully im not sure about wad hp uses
if u can find the make and model, see wad processor it suports,
if the cpu u are planning to buy is supported, u can use it
most probably is liddat