My son has a old computer I built @ 12 years ago. It has a Q6600 cpu . Has a corsair 750w power supply. I forget the rest of the components although the Mobo is a p5 something. All the other components were good components at the time of the build. He plays WOW mostly I think and the computer can just not play them anymore. My question is can I just upgrade the cpu, memory, mobo and graphics and keep the rest of the components or would the new pieces need a complete new system. Thanks folks for any info you can give. If more information is needed let me know.