Unable to connect inernet through wireless

Hi,

I bought a new dell E1505 laptop with dell wirelss 802.11n adaptor in december.

and came back to germany and now i am trying to arcor DSL connection.

It displays “acquiring Network address” and later not connected.

i tried so hard to solve this from various article available on net.

can anyone help me out.

I will be very thankful to ur kind support.

Thanks
HRP