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.
mac address are invalid in both CMOS and Flash
I just spent a considerable amount of time fixing a bad bios flash and I wanted to post this up in case anyone else out there comes across it so they will know what to do. Motherboard is an ASROCK 4CORE DUAL VSTA
After flashing the most current bios to a new plcc chip, I got the error "mac address are invalid in both CMOS and Flash press F1 to continue" on startup. This prevents your onboard nic from working as it can't be talked to without a mac.
So I download the mac address changer tool from ASROCK and used as they said to, but got a "write mac function call fail" error when writing the correct mac address. Apparently something is either wrong with their tool, or that tool does not work for the 4CORE DUAL VSTA.