I used Technitium MAC Address Changer repeatedly on my Windows 11 computer. At some point, Ethernet stopped working whenever I restored the original MAC address, while a random replacement MAC address allowed the internet to work. I later edited the registry while trying to fix the problem, and now the original hardware MAC address no longer appears correctly in Technitium or Windows network settings. The tool reports a replacement address associated with a Samsung device and cannot restore the original. I have already tried several fixes with help from an AI, a friend, and the program's creator. How can I return the network adapter to its genuine factory MAC address, restore normal internet access, and safely remove the MAC-changing software?
2 Answers
The genuine MAC address is normally stored in the network adapter’s firmware, so deleting a Windows registry entry usually does not permanently erase it. Check the adapter’s Details tab in Device Manager and select Network Address, or run ipconfig /all in Command Prompt to compare the physical address. If the value is still being overridden, remove the override, uninstall the MAC changer and its network components, then shut down the PC completely and power it back on. Restarting the router afterward may clear its old DHCP lease. If the factory address is missing even after a clean driver reinstall, use the adapter or motherboard manufacturer’s support utility, or replace the adapter; do not invent a new address and treat it as the original.
Stop using the MAC-changing utility for now and uninstall it. Open Device Manager, find the Ethernet adapter under Network adapters, open Properties, and check the Advanced tab for a setting such as Network Address or Locally Administered Address. Set it to Not Present, Default, or blank rather than entering a value manually. Then restart the computer. You can also reinstall or update the adapter’s official driver from the computer or motherboard manufacturer. Avoid making further registry changes unless you have a specific backup and instructions.
I was changing it because this computer had an internet block, but I did not realize the adapter could be configured without third-party software. I am using Ethernet rather than Wi-Fi.
A random MAC appearing as a different manufacturer is expected when the address is spoofed. It does not mean the computer’s actual hardware address has changed to that manufacturer.