As 4745454b said. The P7P55 LX board is for LGA 1156 processors, while the i7 3770k is a LGA 1155 processor. They simply will not work together. The best CPU available that you could upgrade to on that motherboard would be the i7 875K or i7 880 if you don't plan to overclock much. However unless you can obtain one of those CPUs cheap, I suggest you are better off just simply upgrading to the latest platform.