LAN - ethernet help?

Okay so my wireless is apparently broken and i cant get new router sent for 5 days meaning i have no internet on my laptop for a week. My computer downstairs however runs on LAN and works fine with the internet atm.

I know that you can run more than one computer on LAN right? Well at the back of my router there's 4 ethernet ports so i have put my ethernet cable in one of the ports to try and connect my laptop to the LAN network via the computer that doesnt use wireless.

My computer seems to have picked up that there is a LAN connection but i cant get on the internet... it shows there is excellent signal strength but it doesnt seem to be connecting, what am i doing wrong?

I've searched the web and people who have had similar problems seem to say check your Internet protocol is obtaining automatically. Which it is.

What do i have to do to get my laptop to recognize the ethernet and connect me to the internet?

Help is really appreciated as ive now being trying to fix this for the past 5 hours.