Plug the Ethernet Cable into the port in the wall. (Dorm rooms should have two Ethernet ports, one on each side of the room)
Plug the other end of your Ethernet Cable into your computer.
Once connected, open a web browser (IE, Safari, Chrome, Firefox) and go to netreg.appstate.edu.
Log in using your ASU Credentials and follow the steps to register your device. You will need to re-boot your device after 10-20 minutes for the registration to take effect.