I have an old gateway I am upgrading for my grandparents for x-mas. I have built 2 AMD models and upgraded a compaq laptop with an intel cpu to a dual core but have never built an Intel build. So what I have to work with is a gateway with DDR for ram, the cpu is an Intel Pentium 4 2.8ghz 512 kb cache 800mhz. I want to upgrade this to a dual core, obviously I would have to buy on ebay or something like that. The socket is a PPGA478. What can I do with what I have??