When changing processors you need to ensure that the motherboard can accommodate the change. Certainly the first thing is making sure the new one has the same no. of pins as you mentioned, but you need to be sure the motherboad can handle faster speeds, additional features, and the BIOS is compatible. Since motherboards in laptops are proprietary, you really need to ask Acer about making any such changes. In general I would not attempt it in a laptop and even in a desktop, I'd want to check the specs very carefully. I normally only change the processor when I buy a new motherboard that I know has been tested with the processor. For example I recently learned about a feature called SLAT (Secondary Level Address Translation) which some older processors don't have. Suppose you boot with a new processor and the BIOS sees some feature it doesn't recognize like that? It might just beep a few times and stop before even trying to boot. I5 chips do have the feature, but I mention it as just an example. There can be so many "under the covers" highly technical considerations that the ordinary human would never in a million years think about until they jump up and bite you, it's really best to exercise extreme caution with this kind of thing.