Lost MAC Address After BIOS Rewrite – Need Help Restoring on HP 800 G1 SFF

[jjkevi]

Hi everyone,

I’ve run into an issue with my HP 800 G1 Small Form Factor PC after performing a BIOS rewrite. Everything works except for one major problem — the MAC address for the onboard network adapter is missing.

Here’s the situation:

• Model: HP 800 G1 SFF
• OS: Windows 10 Pro
• Cause: After rewriting the BIOS, the system lost its original MAC address.
• Symptoms:
  • Network adapter shows a generic or invalid MAC (or sometimes blank).
  • No Ethernet connectivity unless I use an external USB-to-Ethernet adapter.
• What I’ve tried:
  • Checked BIOS settings (no MAC override option available).
  • Tried various Intel and HP utilities to restore or inject the MAC address.
  • Looked for NBDMFit tools, but most versions I’ve found are 32-bit and won’t run properly on my setup.
  • No luck so far with registry edits or netsh commands.

From my research, it seems HP uses a special service tool to rewrite the MAC address into the NIC’s EEPROM after motherboard replacement or BIOS flashing. Unfortunately, I haven’t found a compatible one for this model.

If anyone has experience with HP MAC address restoration tools (preferably 64-bit) or a workaround for the HP 800 G1, I’d really appreciate guidance.

Thanks in advance for any help!