From the Course Summary page under Course Options, click on Edit to find the Access Options. In this section the following access options are available:

• Student Enrollment Status can be set to Open or Closed, to allow or prevent students from enrolling this this course.
• Course Access can be set to Regular or Denied, to allow or prevent currently enrolled students from accessing this course.
• The Archive Status may be set to archived or unarchived (Sec. 6.4.37).