I have Compaq SR2180NX with Pentium D 820. It has bad HD. I would like to improve the computer, especially energy wise. Is there a motherboard that will fit easily that accepts the newer dual cores? If not I consider the Celeron 450 for efficiency. I have a Xigmatek 120 cooler and WD Caviar Black that should make this combination low power consumption. I will also install new Windows 7. My question is if my present motherboard is weak link?