HP Pavilion ZV6000 CPU upgrade

Hi,
It's my 1st thread on this forum.
I have a 2 y/o laptop which is becoming slow. I'm working with multiple applications and consider upgrading to a dual core CPU: from 3200+ Venice to 4200x2 Manchester. The skt is 939, which would, theoretically, support a dual core. However, I'm not sure about the BIOS, which is a Phoenix brand.
Does anyone have any idea if this upgrade would work? I'm trying to avoid burning my machine.
Thank you,
Simona

ps: you can reply here or on my e-mail, but I hope that others would benefit of the advices.... that I expect to come !