How Do I Stabilize Internet On A Wired Pc

I have a cable modem connected to a D-Link Router. My desktop computer is hardwired to the router. After ½ hour I lose my connection to the Internet.

I can reboot and then have an internet connect for a half hour. WiFi continues to work normally.

Chrome reports an error message: DNS look up failed. Error Code DNS_Probe_Finishedsd_NXDOMAIN

Cisco System’s Network Magic shows the Internet as working.

Windows Network and Sharing shows a network map with Internet connected.

The Local Area Network Connection status shows IPv4 connected to the internet and IPv6 as not connected to the internet.