I agree with what everyone else said about reformatting being the best way to go. However, I recently did a motherboard upgrade for someone who insisted on not having to reformat and it did work. What you do is after installing the new board, boot the system using the windows CD and select the "repair" option. This will reinstall windows and give you the opportunity to load any new drivers. It ended up working fine for my buddy's system but he was upgrading from a 850 to an 850e chipset board, so the similarity of boards may have affected the success we had. Good luck.