Sorry I didn't get back to your earlier. I have not tried disconnecting wifi because it is physically not easy (the router is in the corner with all kind of junk around it and the desk is in another room). But what I thought right now is I can disconnect the cable from the router and connect it to the cable modem. That in essence would be like not having wi-fi at all. But I am almost gave up to find the solution to this. I suspect (just a guess) that the reason it happened is that when the Docking station "broke" (at the same time when network stopped working) it send some "high" electrical charge to the computer (via network connection) and it damaged the network circuit. I have a surge protector for the docking station but it is a very simple one. I will get a more powerful surge protector now for the new computer and its docking station.

>Have you tried 1-5 below without the docking station? I didn't see any response...
>
>>Curious, what happens if you:
>>
>>1: disconnect wifi completely and disable it
>>2: connect ethernet cable
>>3: restart networking on the laptop
>>4: if the cable still shows no connection, disable it (local connection under networking) and re-enable it and then try again
>>5: can you post your local connection settings? Is tcpip4 and/or tcpip6 enabled (checked under tcp settings) and dhcp enabled for that network card?