Computer help forum: want to boost memory help !!

right in my diffrent post i exsplained what i were getting well now im running

msi forgot witch one motherboard (but its the one that hp used in the pavilion t3529.uk )

it started life with

3.06 single core intel pentiem 4 socket 775
1gb ddr2 memory
160gb sata hdd
lite-on dvd rw dl

but now its running

3.06 dual core intel pentiem D socket 775
2gb ddr2 kingston memory
530gb hdd spread between 4 hardrives
and a sony dvd rw dl

ive checked with hp and serched the motherboard modle up an its says it can only run 2gb memory
im wanting to put 4gb in but it says 2gb is the max but i have a few friends who have motherboards that are only ment to run 4gb but there running 8gb will mine be able to run 4gb ???

i dont want to buy the memory for it not to work :'(

its either that or im buying a new motherboar that will run it and be slighty better then what i have

the one im looking at is asus it will run dual core quad core extreme core were mine only runs dual but there both the same socket

but the asus runs ddr3 memory not ddr2 so yeh

PLEASE HELP !!!!!!!!!!!