No replies?? I also am looking for utility to do this. I recently downgraded my bios using afudos with the /pnbc switch whcih cleared my MAC address. The MAC address that was being reported must have been an invalid one because I couldn't connect to my router even when manually setting the NIC IP in DCHP. I was able to set the MAC back to the original using the NIC driver properties advanced options. I selected the Network Address option and entered the correct address. I'm still looking for a utility to flash the correct MAC back to the BIOS. I tried a suggested program DMI236 but it didn't work with my MB. I would think since afudos is capable of erasing the MAC from the BIOS, it should be capable of writing it back.