home networking help question

I have my home network through the phone line, with a 2wire router. I
don't know what has happened, but all of the sudden my other two
computers cannot get on the internet. Is there a way other than system
restore to remove all traces of a network, so that I can start
completely over I have an external morotola cable modem, hooked up by
ethernet to the modem. One computer is hooked by ethernet to the router,
and it can access the net fie. The other two are hooked in other rooms
by phoneline adapters. the lights on the Homeportal 165 indicate no
problem with the hphone line, butI cann not diagnose the problem./