When am I allowed to retake a course for a grade?

The GMU catalog states:

Except for courses that are repeatable for additional credit, such as special topics courses, undergraduate degree students may repeat courses for which they seek a higher grade. A grade received in a repeated course will replace a grade in prior takings of the same course in the calculation of the cumulative GPA, even if the more recent grade is lower. Repeat rules apply to the same course and to courses designated in the catalog as equivalent. Repeat rules apply throughout a student’s academic history. All instances of courses and their grades remain part of the student’s transcript. Duplicate credit is not given. No adjustment to the cumulative GPA will be made when the grade in the repeated course is W. A grade in a Mason course will not be excluded from the cumulative GPA based on a subsequent taking of an equivalent course at a transfer institution. The exclusion of earlier grades of repeated courses will not change the academic standing or dean’s list notations for the earlier semester. Note that individual programs may disallow students from retaking certain high-demand courses simply for the purpose of improving their grade.

If I receive a "D" in a course intended to satisfy a prerequisite for a CS course, must I retake that course?

Yes. You must retake any course that is intended to satisfy a prerequisite for a CS course if you do not receive a "C" or better in that course.

If I retake a course, which grade shows up on my transcript?

Both grades will appear on your transcript. However, only the better grade of the two will be calculated into your graduation GPA.

How do I obtain an "Incomplete" if I cannot complete the work for a course?

If you know that it will be impossible for you to complete the requirements, you may request the course instructor to give you an Incomplete. The two of you need to have a clear understanding about what you must do to get the Incomplete changed to a letter grade and by what date that material is to be submitted. A written agreement is sometimes used. In any case, the University deadline is the 9th week of the following Spring or Fall semester. Please be aware by university policy, incompletes are given only under extenuating circumstances, and only when a student has performed satisfactorily in the class up to that point.