Per VZW the HD advance call feature is active for my phone line. I activate under Advance Calling settings, turn off and power on phone as instructed. Go to settings and the 'activate' feature has not changed; I don't see an on/off slide. I suspect some other software is in conflict with this process. However the only two apps explicitly identified I do not have - ringtones and Slacker ringtones. Others on my account with same model phone have been able to activate successfully.