Hello,
I HAVE A LINKSYS ROUTER.I MANUALLY CONFIGERD IT AND ITS SECURED IT WILL LET MY LAPTOP CONNECT TO IT BUT IT WONT LET ME ACESS THE INTERNET.I HAVE AT&T DSL.
You need to go into the router configuration and see what the WAN port settings are, if you are getting the right IP/Gateway/DNS servers from the modem. Try power-cycling the modem, then the router.