Is the ethernet port on your laptop enabled? For DHCP? Are the ethernet ports on your router enabled? Is your router set to provide DHCP to local connections? Is anything else connected by ethernet to your router working? What make/model router do you have?
How do I connect an old laptop that doesn't have WiFi with an Ethernet cable? I plugged it in the laptop and the router but it's not connecting.
Which Gateway do you have?