Wireless connection

Hi- I just bought a new Sony laptop but cannot connect to my wireless connection at home. I have another laptop which is connecting perfectly using a PC card. When I go into network connections and wireless connections, my wireless connection is there and correctly named.However when I click connect and enter the security key it responds stating that it is connected to the wireless router with limited connectivity but cannot connect to the net. Have tried various things and troubleshooting tips with no success. I have called NTL (b/b provider) but they’ve been the opposite of helpfull!