My wired internet was working normally about a week ago, but it suddenly stopped. The Ethernet port on my motherboard no longer shows a link light. I tested the cable with another device and confirmed that the cable works. I also bought a UGREEN USB Ethernet adapter, but that does not work on this PC either—even though both the adapter and cable work correctly with a laptop and an Xbox.
I have already tried flushing DNS, releasing and renewing the IP address, restarting the PC, changing Ethernet cables, resetting the network adapters, rebooting the modem, disabling the proxy, reinstalling both the motherboard LAN and UGREEN adapter drivers, and testing multiple USB ports. Flushing DNS and renewing the address briefly restored the connection for around 20 seconds, but it stopped again and now neither adapter shows a connection.
What else can I check? Could something on the PC be affecting both the onboard Ethernet and the USB adapter?
1 Answer
Since the motherboard port and the USB Ethernet adapter both work with other devices, the cable, router, and adapters are probably fine. That points to something on this PC that both network connections share, such as a power-state issue, Windows network filter, or security software.
First, try a complete power drain rather than a normal restart: hold Shift while selecting Shut down to bypass Fast Startup, turn off the power supply switch, unplug the PC, hold the power button for about 15 seconds, then reconnect everything and boot it up. A network controller can occasionally get stuck in a bad hardware power state.
After that, try Windows’ full Network reset under Settings > Network & internet > Advanced network settings > Network reset, then restart. This can remove leftover VPN, antivirus, or other network filter drivers affecting every adapter.
I already tried the Windows network reset, but I’ll test the full power-drain procedure. I have used Proton VPN for a couple of years without problems and don’t remember installing any game-networking software recently.