Private Line gives you the ability to restrict whose calls can get through to you. The only requirements are that a voice modem and sound card are installed in your PC. Private line also functions as an answering machine.This program works with regular phone lines, not over the Internet. There is no need for Internet access to use it. You can deactivate all of your telephone ringers and let private Line handle all of your calls. When it answers the phone it greets the caller with a voice message. The caller is asked to enter his or her 4 digit PIN. You provide PINs to the people you want to call you. If they enter a valid pin then they are notified that the number entered was correct and that you are being notified at this time. Your speakers will ring just like a phone. If no one answers then the caller will be given the option to leave a message. If the caller does not have a PIN or enters an invalid one then it will go directly to the message option. With this program you will never be caught by someone you don?t want to talk to.