In my experience, the “Unidentified network” error is the most common problem if WiFi is not working. This error usually means that the automatic assignment of the IP address settings through the router’s DHCP server has failed. The DHCP server might be down or malfunctioning. However, in many cases, the Windows DHCP client is the culprit. To check which is which, you can try a second device to see if automatic IP address assignment works. If other devices can connect to the DHCP server, you have a few options.
First, check if your WiFi adapter is configured correctly. Go to Network Connection in the Networking and Sharing Center (see instructions above), right-click the WiFi adapter, navigate to Properties, and verify that TCP/IPv4 is set to “Obtain an IP address automatically.” If that is the case, check what IP address has been assigned to your WiFi adapter. Open a command prompt and type ipconfig. Search for “Wireless LAN adapter WiFi:” in the output. If your IP address starts with 169, something went wrong. Automatic IP address assignment failed, and that is the reason for the unidentified network message.