Cannot connet to Skype

Hello, Ok I have used Skype many times in the past but this one I cannot get. The window firewall is off because of Nortons. I set the program controls in Nortons to Allow for Skype. I have reset the router. I have one computer that will connect on this network and one that will not. I have tried the suggestions from Skype. It is Windows XP with Skype 4.2