Unless it's physically soldered onto the motherboard (unlikely), it should be theoretically possible. However, you also have to take into account whether or not the motherboard (BIOS) supports the QX9300 or other quad cores (look for answers on Google), and whether or not the laptop can supply enough power for the quad core and dissipate enough heat. Generally speaking, going from a slower dual core to a faster dual core is safe, but going from a dual core to a quad core in a laptop may be asking for trouble.