Cant connect to internet!!!

[pandaking]

I have had 2 computers running happily through my router for some time. I then added a laptop whci connects wirelessly and that worked fine. Then my mobo blew and after it got replaced I got it back and it came back with no local area network thingy (technical). I am now trying to connect my comp and it won't work. I recently made a new pc and did (as I have been told you have to) the old routene of turning of comp at mains, turning off router, and then the set top box. You then start up the set top box, leave it a while, trun on the router, leave that a while and then finnally the pc. When you then try to connect to the internet NTL will load up after a few second and you enter your information on this strange kind of website and then it all works fine. I then took the pc to work and it worked perfectly there. I then set up my repaired pc and am stuck. How can I get it connected. The only connections in the network connection screen is two both named '1394' which I believe to be firewire. I have allways connected trough ethernet. Can anybody please help me. I cant see what I am doing wrong, or how I can fix it. I need to create a local area connection I think. Any ideas...