My Ethernet connection stopped working after a power outage. The first time this happened, unplugging and reconnecting the cable fixed it, but now that no longer works. I've updated and reinstalled the Ethernet drivers, unplugged the cable, power-flushed the computer, and run the network troubleshooter without success. I also tried a different port on the router. Is there anything else I can check before buying a Wi-Fi card?
3 Answers
In Windows, disable and re-enable the Ethernet adapter, then run ipconfig /release, ipconfig /renew, and ipconfig /flushdns from Command Prompt. Restart Windows afterward. If it reports that Ethernet is connected but you still have no internet, check whether the computer received a valid IP address and test another cable or device to separate a Windows configuration problem from a failed adapter.
Test with a different Ethernet cable and, if possible, another device on the same router port. Since the problem started after a power outage and another router port didn’t help, the computer’s Ethernet adapter or the cable may have been damaged. A USB-to-Ethernet adapter is usually an inexpensive workaround if the built-in port has failed.
I tried another router port and it didn’t work either, so damage from the outage might be possible.
Try rebooting the network from scratch: shut down the computer, unplug or power off the router for a minute, let it fully reconnect, and then start the computer again. This can clear up issues with the router assigning an address.

I ran those commands and Windows now says Ethernet is connected, but I’m still offline. That can happen when the physical connection is detected but the adapter isn’t getting a usable network address or the router connection is still failing.