which network interface (physical) does a router use? ANd as per teabags, the other computers wll be able to access the interet even when the computer is on. Let me tell you that the modem I use is a USB modem which functions only in Windows. ALso, since it is a USB modem, I do not think that this could be anyway directly connected to the router!

So the concept is not fitting well in m mind. Can someone please tell me of a diagnostic software which could tell me the problem or that how to use a proxy in order to share the IC than making me buy a router, please ? Till them I would like to find something on the internet by myself.