Hello,
mPGA479M is 479-pin Micro-FCBGA.
In most cases, you can successfully upgrade a laptop's processor. On my previous HP nx7300 business notebook, I upgraded the Mobile Intel Celeron 1.73 GHz processor to an Intel Core Duo 1.83 GHz processor. One problem though, because the notebook's chipset didn't support dual-core, I had to disable dual core support in the BIOS in order for the laptop to be able POST. In effect, I upgraded to an Intel Core Solo 1.83GHz processor (as reported in CPU-Z) which is still an improvement since I benefited from a slight clock boost, EIST, larger L2 cache and lower power consumption.
When planning to upgrade a laptop processor, you need to be doubly sure on what socket you have. Use CPU-Z to verify which processor you have. Better yet, look open up your notebook and look at the label on your CPU, and the socket (which usually has the socket type engraved onto it).
It might also be a good idea to check if anyone else with the same notebook model has successfully upgraded their processor, and to which processor.