Setting up a new ethernet connection

hello guys,

As for now i have a modem which is connection to my PC via USB cable.

I wanted to connect my modem (arris 550b) via ethernet cable, however my ethernet port in motherboard is broken. So i borrowed another ethernet card (or whatever it is called) (intel 100 + adapter) and connected it via ethernet with modem.

I called my internet provider and told them to help me setup it. However my modem cant get their IP settings which they are sending to it. As a result modem cant connect to the network.

any ideas what can cause such problems?
also, my internet provider confirmed that there is a connection between card, cable and modem. i am using windows 7 ultimate 64bit

thanks