Network Cable is Unplugged

I have a Laptop with WinXP, Although, the network cable is plugged in, it still showing that icon that is unplugged.

The driver for the network card is okay, the network cable is okay. Everytime I disable the network and enable it again, it will show the connection speed at 100 then within 1 or 2 seconds, the message says that the network cable is unplugged. But damn it, its plugged into the slot.

Help me solve this problem.
Thank you,
Tilson