I have a Sony VAIO VGN AW11S and I was wondering can I upgrade my CPU to a faster one. I don't know much about hardware and I can't find anywhere that says the size or 'fit' of the cpu if that matters or not. Currently I have an Intel Dual Core P8400 2.26Ghz but I want to upgrade, but is it worth it and will it have much of an effect?
Well, I don't think you can replace laptop CPUs, although with the socket P CPUs, you might be able to. You might be able to upgrade to another CPU which has the same 25W TDP and voltage rate - 1.0V - 1.25V, something like a Core 2 Duo P8700, however, I don't think it would be worth it, although it would speed up some applications a bit.
That laptop should game pretty good it is better then most are since it has a half decent graphics solution in it. The only thing you can really do to laptops is upgrade RAM and change Hard Drives other than that you cant do anything.