my friend brought his pc over to my house and i have road runner. we plugged his pc into the wireless router with an ethernet cord and put the ip address and other information in so it would work with my router to get internet. he then took his pc home and plugged his dial-up cord in to find out that it didnt work. when he plugs the cord into the computer the phone no longer works, even if your offline. he then tries to connect and it says theres no dial tone. you take the internet cord out and the phone works again. what happed?