salam Plz help me in installing the modoem in windows Xp

my modem is conexent 6793-12. how ever it is automatically install in Xp.But when i make the dial up connection. it gives Error 777.
plz help me if any one has a modem as above plz mail me back at raees.gul786@gmail.com.
plz tell me what is the setting of this modem