If the computer or motherboard is still under warranty get it replaced. I had same issue with asrock board and was unable to repair. eprom/bios has been damaged/corrupted and only a few boards will let you change mac in bios. reflashing bios might work but I doubt it. you need a bios flash that alows you to set mac before flash. this needs to match the mac that is printed on the board (usually on a sticker near lan port. Your onboard ethernet likely wont work until this problem is fixed. You will have to buy an ad on NIC card to access networks/internet. DO NOT ATTEMPT TO REFLASH MAC UNLESS YOU KNOW WHAT YOU ARE DOING! if you screw it up your computer will not boot.
You are about to answer a thread that has been inactive for more than 6 months. If you still wish to proceed, please ensure that your posting is original and does not duplicate or overlap any prior responses to this thread.