After my internet provider restored my TV channels, my router's Wi-Fi settings were reset. Wi-Fi works normally, and one of my two wired PCs connects without any problems. However, the other PC reports that Ethernet doesn't have a valid IP configuration. ipconfig shows no default gateway or DHCP server, and the router lists that computer with a blank hostname and device type. I've already replaced the Ethernet cable, tried every router port, confirmed IPv4 and DNS are set to obtain addresses automatically, updated the LAN drivers, enabled the adapter, and uninstalled/reinstalled it through Device Manager. What else should I check to determine whether this is a Windows configuration problem or a failing network adapter?
3 Answers
Trying every router port and replacing the cable rules out most basic connection problems. Check whether the PC’s Ethernet port shows link lights and whether Windows reports the cable as connected. If there are no lights or the adapter appears connected but never gets a DHCP lease, test with a USB Ethernet adapter or another network card. That can confirm whether the built-in NIC or its hardware is failing.
Since another computer works on the same router, the provider and router are probably fine. On the affected PC, make sure both IPv4 address assignment and DNS are set to automatic, then run ipconfig /release followed by ipconfig /renew. If renewal still produces no DHCP server or gateway, check the adapter status and reinstall the Ethernet device in Device Manager before rebooting.
I already confirmed the automatic settings, and the adapter is enabled. I also removed it in Device Manager and restarted, but the PC still doesn’t receive an address.
The blank hostname in the router’s device list is not necessarily the cause; it usually just means the PC has not successfully completed DHCP. You can try a full network reset in Windows, restart the router and PC, and verify that no static IP, proxy, VPN, or third-party firewall configuration is interfering. If the reset changes nothing, hardware testing is the next logical step.
If a USB adapter works immediately, the onboard Ethernet port is likely the culprit. If it also fails, reset Windows’ network stack and check for unusual firewall, VPN, or manually configured network settings.