If your system is an emachines with ecs motherboard which has an nvidia chipset for Intel cpus, your guess is as good as mine. Have you tried contacting emachines? I don't know what cpu you have now; I would guess you would be safe with a 1066 fsb quad core, such as the q6600, which you can sometimes find used. Newer wolfdales might be a problem, since no bios update is available for this board.
hey thankyou for the help! iv emailed parkard bell and with abit of luck they will get back to me, at the moment im runing a intel celeron E1400 Dual-core 2000mhz and i been told it abit poor so hopfuly they can point me the right way! thanks again for the help and il give you a update with u wish?