So I just got a new isp. They sent me the router and all that stuff.

I have a router plugged into my phone line to receive the internet connection.

From that router I get a wireless signal that gives my parents laptop its connection, the laptop is fine.

From the same router I have an ethernet cable connected to my sisters PC and she gets a connection, thats fine.

But when It comes to my pc, I also have an ethernet cable going directly from the router to my pc just like my sisters set up, except my pc isn't connecting. It's all set up fine but I don't know what the problem is.
I go into control panel - network connections, and there is nothing there except an icon with the numbers 1364 or something like that. I know there should be an icon called (name of router) but it isn't there.

Is there something wrong with the ethernet cable, or something wrong with my pc?

P.S. About 6 months ago I had to take out a network card to put in a sound card as there wasn't any room left. At the time I didn't think the Network Card was needed as my old ISP was working fine. ( I had a modem connected directly to my pc via USB)

Do you need an network card for ethernet cables?

on your machine what's the ethernet cable connected to if you have no network card?