If the screen looks like the image below, use the StudentID@stu.gcsnc.com (ex.: 123456789@stu.gcsnc.com) as the username and if asked for a password, use the birthdate, MMDDYYYY.
If the sign in request looks like the image below, enter the email address (StudentID@stu.gcsnc.com).
If that does not work, try turning the Chromebook off and back on again and logging in again.
If that does not work, call 336.370.8179.