I used Technitium MAC Address Changer repeatedly on my Windows 11 computer. At some point, restoring my usual MAC address caused my Ethernet internet connection to stop working, while using a different MAC address allowed it to work. I later deleted a registry entry while trying to reset the address, and now my original MAC address no longer appears correctly in Technitium or Windows network settings. The program shows a different address, sometimes identifying it as a Samsung device, and its "Restore Original" option fails. How can I return the network adapter to its factory MAC address, get the connection working normally again, and remove any remaining override?
2 Answers
Stop using the third-party changer for now. Open Device Manager, expand Network adapters, open the Ethernet adapter’s Properties, and check the Advanced tab for a setting called Network Address or Locally Administered Address. Set it to Not Present, Default, or leave the value blank, then restart the computer. If that does not work, uninstall the adapter and its driver from Device Manager, restart, and let Windows reinstall it. You can also use Windows’ network reset as a last resort, although it will remove saved network settings. Afterward, restart both the PC and router. The factory MAC address is normally printed on the adapter, motherboard label, or in the adapter’s details; a software override cannot permanently change the hardware address.
A normal Ethernet adapter should not need its MAC address changed regularly. The address shown in Windows can be a locally administered override rather than the physical factory address. Check the adapter’s status or Details tab for “Network Address,” and remove any override there. Also check for a Technitium network filter or service and uninstall it after restoring the adapter settings. If the connection only works with a spoofed address, the block may be enforced by the router or network administrator, so changing the address is not a reliable fix and may violate the network’s rules. If this is your own computer and network, reset the router’s DHCP lease or remove the old device entry instead.
I was changing it because the computer’s internet access had been blocked, and I was trying to get around that restriction. I’m using Ethernet rather than Wi-Fi.