Hey guys. I'm running P5N-E SLI 1.XX 3.15 gigahertz Intel Core2 Duo with 2x 1GB RAM. Also running Win XP 32 bit, but want to upgrade to Win 7. I believe the motherboard can handle up to 1333 MHz. I'm running 800 MHz now. Not sure if I should buy all new RAM or just add to what I have. Any suggestions?