I have a Toshiba Satellite C855D that is running Win 8. I comes up to a login screen that has an email address for the user name. I'm trying to switch user to either the administrator account or another user name that is in the system. However, my only options on the login screen is to reboot, shutdown, or sleep. I don't have an option to change the user name. Does anyone know how to change the login name or how to login as administrator?