Inspiron 1545 Vista Home Basic Not Recognizing Internet Connection Thru Ethernet Port

In my dorm room, I have to connect to the internet through an ethernet cable plugged into the wall. My roommate's computer recognizes the connection and she gets internet in both the port on my side of the room and the one on her side. My computer doesn't recognize the connection with either. Obviously, there's something going on with my computer, as we've discovered both ports and ethernet cables work. Any experience or ideas with this?