The first step for course registration is to reserve a Permit to Register. See the Reservations tab for more details.
There will be seats open in courses during every Permit to Register window, so there are no advantages or disadvantages from one week to the next in terms of course availability.
By the time your Permit to Register date arrives, you will have completed the Pre-Registration Checklist and met with an academic advisor. During your Permit to Register window, the USC Web Registration system will be closed to other students, except those who have reserved a spot during the same window.