According to your system specs: http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=en&cc=us&docname=c00280665, your motherboard won't work with core2 duos. You need to research the board carefully, especially oem boards, before upgrading the cpu. Many oem boards won't work with newer cpus; your 915 chipset board is too old. If you change to a non compaq motherboard, then you may need a new windows coa unless you've already upgraded your software.