Alright, let's take this one problem at a time.
First, hardware. Is this a new computer, and is it custom-built? Does Windows boot okay? Did Mandriva 10.1 work? What are your hardware specs? What is your power supply wattage, and how many fans do you have? Have you checked the BIOS to see if the fans are working at a decent speed?
We'll tackle your network card after we've got this solved.