I cant believe the answers you guys gave to the OP. If his laptop has a socket G1 processor, you can upgrade your laptop from an i3 or i5 to i7 socket G1 processors as long as your laptops bios supports the processor. They normally have the same cooling system accross the different SKUs (ones with discreet GPUs have different cooling tho)
Safest way to do this is to review the different SKUs of your laptop and just choose which CPU to buy.
For reference, my wife's laptop had an i3 330m and I was able to slot in an i5 460m, while giving the laptop a nice wipe down in and out (dust build up cause throttling, clean yours too!)