Ubuntu – My Dell Inspiron 1501 wont connect to any network (wireless or wired)

I just recently installed Ubuntu 12.04, replacing windows vista on my Inspiron and it wont connect to the internet by any means. It won't detect any wireless networks and when I try the ethernet cord, I can see "wired connection 1" in the network manager but the symbol on the panel is a wireless signal with 0 bars. Furthermore when I open firefox, it says there isn't a connection. What should I do?

(NOT AN ANSWER)
Ok so I've entered the required information, and changed the router settings so that it uses a static IP. Still the Inspiron refuses to recognize the connection. When I pull up the network manager, the only connection I see is "Wired Connection 1" but it says it was last used one day ago even though I currently have it plugged in. It's like the computer doesn't even recognise the attached ethernet cord.