Can't connect using ethernet cable? Please Help?

Ok, I've been using my Dell Dimension C521 for about 3 years now using a wireless card and connecting to a wireless connection in the house. I now moved and tried to hook my Dell up to the internet using a direct connect ethernet cable from the cable companys netgear router. When I plug it in, on the back of the computer a light comes on right where the ethernet cable goes in so I know it accepts it. But I can't get a connection to the internet. Nothing pops up on my computer when I plug it in prompting me to do anything and I've tried to make a new connection using the new internet connection wizard. I did remove my wireless card (motorola). And I know the connection works because I'm using my lap top with it right now. When I plug it in the back of the lap top it auto connects and I have internet right away. Any help on what I'm doing wrong? Thanks in advance