Upgrading a laptop processor is a bit complicated, it's not as easy as upgrading RAM or hard drive. There are several things You need to consider first:
- Temperature. Your laptop heat sink is designed for specific processor model, so it can handle the heat. If You insist to upgrade, the processor gonna suffers from overheating, and, you can't just buy a bigger or better heat sink, because laptop heat sink have unique shape that won't fit into Your laptop.
- Power. Can Your laptop power adapter handle the required power?
- Not worth the money. Because your laptop heat sink can't handle the heat from a much faster processor, your only option is to buy a slightly better processor, e.g: Mobile Core i3 2.2GHz to 2.4GHz. For that insignificant 0.2GHz increase it will cost you 125 dollars.
My suggestion: save your money, research for good affordable laptop for a while, and when you've found Your desired laptop, sell Your laptop, and used the money + saving money to buy a new better laptop.