Trouble connecting to orange livebox

[Darey]

Im setting up a wireless connection with the livebox for a friend, I've managed to get the laptop connected ok but im having trouble with the main computer connecting through a usb wireless dongle.
It says its connected but its acquiring network address, any help would be appreciated.

 

[Darey]

Laptop is on vista and connected once I put the wep key in, the main computer is on xp.
I'll try turning the security off crazyDAJT and see what happens, I've just left there house to test the dongle in my computer and it picks up someones network and connects no problem