I have a 2005 vintage desktop with an ASUS, P5W DH Delux MB and a same vintage Intel Core Duo CPU. I tried moving to a Core Duo, Quad, but the MB just couldn't handle it even with updated BIOS. It has a USB PCI card, a PCIE wireless/ bluetooth card. The case has been altered to include USB-3 sockets built-in, so I want to keep the case and PCI cards. I've been thinking about putting in an Asus P5G41C-M LX and an Intel QX6850 Core Duo, Quad, I know these work together. Although I've built seven Desktops, and am living on Social Security, If anyone can set my sights higher for a used MB/CPU upgrade, I would like to hear about it. I suspect I'm setting my sights too low. Thanks.