Your instructor needs to synchronize their gradebook to get the latest registration information. It may be that your instructor has not done this since you registered. If you are sure that is not the reason, verify that the student ID you used to register matches your instructor's roster. To do this, you can show your registration confirmation printout to your instructor. If you do not have this printout, use the Remote ID Lookup tool to generate a printable confirmation. Finally, make sure that you have registered in the correct location. Some schools want students to register through their Learning Management System (such as Blackboard, Moodle, etc.) rather than the iclicker.com site. Check your syllabus or ask your instructor to make sure you are registering where you should.