alright, clowns get back in the car. To prevent you from doing something stupid, NO, a Pentium 4 cpu will not work in your B120. Intel had three socket 478s (actually 4, but one was named socket 479 despite using only 478 pins), a desktop version called socket 478 that Pentium 4 CPUs used, and two special mobile socket 478s, also called socket M and socket P. Let's not confuse this socket M or P with the Frankenstein laptops running desktop pentium 4 socket 478 CPUs back in 2002-2003. Socket M is a last generation mobile socket, being replaced by socket P, which ironically also has 478 pin cpus, but the missing two pins on the cpu are in a different location, making it impossible to plug a socket M cpu into a socket P socket. Okay, you can safely forget all that crap above. All you need to know is that you need to find a socket 479 processor. pretty much any Pentium M will do, but to be on the safe side I suggest you find one with a 400MHz fsb. Unfortunately, your laptop will not work with Core Duo or Core 2 Duo or Pentium Dual Core CPUs. A Pentium M cpu is as good as it gets for you I'm afraid (note it's "M" and not MOBILE, there is a big difference between the two. You want the CPU with the RECTANGULAR chip in the center, not a square).