[Question/Help] - Add back MAC and serial [known location] to Aptio IV / Asus / 25 SPI Flash [resolved]

I could go into detail about how I got here but suffice to say I messed up and learned my lesson.

System: 10 year old Asus board, Intel 8 series, Aptio IV bios, 25 SPI chip

Problem: I accidentally zeroed out the MAC address and serial number on 2 of 3 identical model boards. I know exactly which line the hexi goes in the BIOS file, and I have the serial number logged and verified. I assume the MAC I can just put anything, doesn’t matter, as I don’t know what it used to be.

Question: What program could I use to update the two lines to add back my serial number, and enter something in the MAC address field?

More background: I have three identical Asus Intel 8 series (Q87) motherboards (retired business desktops). I modded the BIOS to support NVME boot, flashed the wrong file (which I didn’t realize until after the second board), and ended up zeroing out my serial number and MAC address on the first board. Take 2, and the flash failed on the second board, so I pulled the chip from the board, erased, and reprogrammed with the wrong version of the modded nvme BIOS. After booting them up I discovered my error. Anyway, long story short, they are both up and running now, both support nvme boot, but unfortunately I now have 2 boards with identical zeroed out serial numbers and MAC addresses. I pulled the BIOS file from my working PC, and located exactly where the serial number and MAC address go in the bios file (by cross referencing the known serial number and MAC address from the third PC and locating them in the BIOS file). I verified my serial number for the remaining two boards with Asus’s support site and the label printed on the motherboard, and I guess I just need anything for the MAC address. What program can I use to edit the two lines to add this zeroed info back?

The MAC address should be easy, can put anything there, the serial needs to be converted to hexi, and then I assume I can just drop and insert it with the right program, then verify with wmic.

But I am new to this and not sure what I would use to manually edit a line of hex code. Not asking for a handout, I would like to learn to fix it myself if someone could guide me in the right direction.

Also, for anyone who wants to see the results of my blunder, here is a photo showing the zeroed out serial, and the MAC is just 8’s.

FD44Editor allows to enter UUID, MB Serial Number, as well as the LAN Mac Address on any ASUS bios.

You can find it here

Thank you. I’ll give it a try this weekend. Unfortunately, the UUID was also zeroed out but I have no idea how I could figure out what it used to be before. So I was planning on leaving that all FFFF.

I think I’m stuck because I can’t figure out what my UUID is. I edited the bios and I am able to get the motherboard serial number to display in wmic now, but I have no idea what my MAC address used to be, or my UUID used to be (the trailing digits of the UUID are the MAC address which, again, I don’t have). So if I got the UUID, I’d be all set.

Does anyone know would this info be stored anywhere on the hard drive or reconstruct able from the Asus motherboard stickers? I looked at all the stickers on the motherboard and I see no way to ascertain what those numbers used to be from the stickers.

The MAC is the last 12 digits of the UUID this is a unique ID, the Q87M-E has any label on ATX connector?

EDIT: Yes there is no UUID labels on the motherboards, i said only that part of it has the MAC. There is some labels called PPID with partial MBSN. Glad you worked it out.

This thread is resolved now. I was able to retrieve the full UUIDs including the trailing MAC address for both PCs, add the info back to BIOS, reflash, and regain my windows activations. Thanks!

To answer your question, I did have labels there, but the labels only included the partial serial number, and not the UUID, as far as I could decipher. I had to go to asus.com support to get the full serial number.