Printer Works But Fax Does Not

I reinstalled windows 7 home premium 64 bit. Then soon after, my printer checked out ok but the Fax will not work. Its a HP model 4500 printer/Fax. When I do a test fax, it passes all but one test. The error indicates that I am using the wrong phone cord wire and to install the correct one. The correct one is a 2 wire phone cord. I no longer have the original cord. But the install instructions...