To register for the conference, you require a Personal Information Number (PIN). If you have submitted a paper to the conference, you already have a PIN and password and you can use the same information to login and register.
If you know you PIN/password, select the conference you are registering for from the drop down menu (even if there is only one conference), then submit your PIN and password and follow instructions from there.
If you do not have a PIN or have forgotten your password, follow the link(new PIN) to request a new PIN or update your personal contact information.