Cannot connect to the internet using ethernet port

Hi...

I don't know if anyone has encountered this kind of issue but I really need help as I have no idea what caused this problem.

I can't connect to the internet using the (ethernet?) port in my laptop. I'm not sure. I'm somewhat a noob in this issue. (The ones you connect to your desktop or laptop in connecting to broadband internet). Anyway, I can connect to wireless connections with no problem. However, when I try to plug in the wire from the broadband internet to my laptop, it will not detect the connection while my friend's laptop can connect to it with no problem. I have also checked the network adapters on device manager and I see that some of the adapters have a '!' sign beside it. I tried to update them but an error message pops up like 'Windows encountered a problem installing the device driver...". After that, I tried to google in order to resolve this problem and I found one that states to boot your laptop to safe mode and install it from there. When I booted it to safe mode, it seems that the one of the network adapter with the '!' on it was gone and there was an 'unknown device' there when it was not there before. I tried to update the other adapters with the '!' but to no avail. I then rebooted it again to normal mode and the network adapter (which I believed was for the local area connection) was totally gone and I really have no idea what happened. The problem is, my friend will be gone and I won't be able to wirelessly connect to the internet. So that means I have to utilize the ethernet port and it doesn't seem to work when I connect the broadband to my laptop. Please help.

 

Taking a stab at it here.
Has the connection ever worked before?
Have you tried a hard reset of the connection?
Leave the cable connected to your machine. Power off the machine.
Unplug power from your cable modem. Leave off for a few minutes.
Power modem back up.
Once all lights are burning steady, power on the laptop.
Nothing to lose by trying.