Motherboards

I built my pc about 3 yrs ago, and the motherboard is bad-I think this because none of the onboard ports work except the psi slots-no usb's work, but all of my cards work including video. My LAN is questionable because I use a wireless adapter through an added USB extention card which is of course plugged into the MB. the CPU is a Intel 2.4Htz, I have 1.5 G ram + 1 slot expantion, 160 G HDD, exceptional video card(GForce-dont recall exactly_has a fan) None of the USB ports work that are built into the case. I have already spent $150.00 in reairs, and I still get a blue screen of death every time I attempt to use the machine. Please recommend -ps: unsure of exact mother board currently used. I'd like a recommendation to replace the one I currently have over replaceing the computer.