You would need another motherboard to accomadate the new CPU. Also, that new motherboard will take DDR and not SDRAM so you will need new memory. You would be better off saving and doing a full upgrade from scratch.
A+, Network + , HP Certified Tech and MCP
Specs: AMD Phenom II X6 1095T, Asus M477TD, 8GB GSkill Ripjaws DDR3 1600 7-8-7-24 1T, 128GB Crucial M4 SSD, ATi HD4650, W7, 27" HL272 Monitor