Is your wireless network currently secured, or open? I would recommend unsecuring it at first to ensure there is no difficulty connecting. Once successfully connected while unsecure, you could then secure the wireless network for continued use.
Additionally, check the Internet/connection settings of the router/gateway you are going through. Sometimes when it calls for PPOE connections (depending on service provider) I change it to DHCP at the router level and I connect right up. What brand laptop do you have some have a external switch my toshiba has on on the side some times i forget to turn it on.