No internet on a wired (cabled) computer

Check the network cable is firmly plugged in at both ends: the computer and the wall or floor socket. The light next to the socket on the computer usually blinks when it's connected.
Try a different cable or socket if you can.
Restart the computer.
Can you reach anything at all? If shared drives work but websites don't, it's an internet problem rather than your cable. Tell us in your ticket.
If you're at home, restart your home router: switch it off for 30 seconds, then on again, and wait a few minutes.