The most important cables only FIT one plug. If it fits in one but will not fit in ANY others. Thats probably where it goes.
If you need to know which wires for your case such as front usb slots try this pinout diagram
Otherwise you will need to be more specific.
You could definitely try updating your Bios to the latest version. Which you can download from here:http://www.msi.com/service/download/bios-10230.htmlMake sure you have installed all the drivers installed, especially the chipset drivers.Personally though if it isn't a Bios problem then I suspect that at least one of your capacitors on the motherboard is going out. It appears to have the old style capacitors installed which were less durable than most made for today's motherboards.The fact that it freezes after a few hours really make me think capacitor problem or a memory leak.