Dial up option greyed out in New Connection Wizard

I am trying to set up an internet connection on my fatherinlaws computer. I can click on things and get to the point where it says dialup using a modem, another choice and broadband. I need the dial up by modem choice but it is not lit up. The only choice that is lit up the broadband one. It is clicked but you cannot unclick it. What can I do so that he can use the internet that he has already paid for? The computer uses windows xp and is previously owned.