Core 2 Duo E8400 (3.00GHz,1333FSB,L2:6MB,65W,rev.C0):
Compatible since Bios: 0501
You can ask the retailer what bios it ships with.
(info from Asus CPU compatibility website)
If you need to Bios update with your P4, download the latest bios from the asus support website (it will be a .zip file).
Unzip it onto a USB flash drive and rename it to less than 8 characters, if it's too long it won't work.
When your bios starts, go to tools, and select asus EZflash. Then select the bios file on your usb from the list and it will automatically update your motherboard. (Note that your USB flash drive must be formatted as FAT32 to be recognized, but most are anyway..)