HELP ME PLEASE!!!!!!!!!!

i recently bought a pentium d 805 proc and a asrock 775dual mobo with bios ver 1.4, i've got a 550 w psu, windows xp prof sp 1, when i start up task manager or cpu-z i see that only only of the two cores of my pentium d 805 is running, the v-core voltage is also 1.15v wich is much to low is think, in toms reviews i see the d805 running on 1.36v as default.
Can anyone please help me by telling me what to do to get my second core up and running. any ideas????

asrock 775 dual via880-pro chipset bios ver.1.4
box cooler, but want to get a Zalman 9500
sapphire ati 9550 radeon 256 mb
creative x-fi
qtek golden dual fan 550w psu
windows xp prof sp1
ide hd 13,6 gb maxtor
ide hd 83 gb ibm
sata hd 200 gb maxtor

This is what i have in my pc, can anyone please help me!!!!!!!!!