@Roshanlal12 

Hi,

If it is only the computer doesn't work, then you may need to check the settings on the computer itself but not blame the router.

Is the computer connected to the router via cable or Wi-Fi? If it is cable, check and make sure the cable is good and qualified, then check if the computer has obtained an IP address from the router like mentioned here.

If the IP address is correct, then try to do a ping test, ping the IP of the router first, then ping 8.8.8.8, then ping google.com. If pinging the router IP and pinging 8.8.8.8 are successful, but pinging google.com fails, then change the DNS servers on the router to 8.8.8.8 and 8.8.4.4, then check if you have internet again.

This is the guide for your reference to do the ping: How to Use the Ping Command.