dial up problem

I am trying to help out a friend with his computer and I got it all straightened out and running great except when he tries to go online, when he clicks on his explorer icon and it dials his internet connection and says connection made verifiying user id etc. a box pops up that says post dialing connection and it has two buttons on is f-7 to continue or f-3 to cancel and if you don't hit the continue button whithin about 5 seconds the box goes away and it starts dialing again and every thing repeats. how can I get rid of this problem?