Inspiro - unable to get IP address dynamically

I am trying to connect to cable internet but the ipaddress of my inspiron 1100 laptop simply wont change to pick up a dynamic IP. I tried out verifying all the TCP/IP settings and also tried the network conection wizard and IE options. Nothing would help.

Please help me by telling how to overcome this problem. Should I re-install any drivers or OS to easily rectify this ?

 

Thanks in advance.