Problems with my ethernet connection between my computer and my wireless modem

[DonnaMcK66]

I have recently had to replace my wirelss modem, due to an electrical storm. The trouble is now the new modem won't recognise that there is an ethernet connection between my computer and the new  wireless modem/router. The cable is physically connected tot he modem but the port light is not on. There is nothing wrong with cable as I have plugged in my old non-wireless modem via this cable and it has worked (I am connected to the internet now using this cable and old modem). When I trouble shoot the connection problem it is saying the ethernet cable is unplugged when it is not. Changing the cable does not solve the problem, when I took the modem back to the shop they tried it on their computer and it connected and worked no problem.
I gave tried everything from system restore to a date pre-electrical storm,updating drivers, resetting and manually reconfigering the modem. On a couple of occasions I have been able to get a signal (the port light is on and I can connect to the internet) only to return to my computer and find that the port light has gone off and there is no longer a connection. I thought that maybe the modem was not compatible with my computer for some reason and so changed the brand (Netgear to D-Link) still no joy. HELP!!!! 

[truenorth]

I want to make sure i understand your issue correctly. So due to electrical damage you had to replace your modem. isp provided and dsl is that right? I am not sure what you are referring to in terms of the hardware as you seem to be using modem and router interchangeably. I know you have a modem but what is the reference to "router"? Sometimes DSL modems have a built in router. In my case i have an ISP modem but i have a separate router that is capable of both wireless and cable (Ethernet) connections. You keep referring to a "wireless connection but then appear to be saying that you are actually connected from the computer to the "modem via a cable. So where does the issue of "wireless " come into it? If you have a modem/router capable of wireless transmission and a computer that has a built in wi-fi (such as most modern laptops) then a search for an available network should find your modem/router. If the computer doesn't have a built in wi-fi receiver you will need a wireless dongle to receive the modem/router signal. If the latter is the case you will need to have installed software for the dongle. So come back to us and elaborate on what it is you actually have and what it is you are trying to achieve re your connection to your ISP. truenorth