If a student needs to retake a quiz that they have already attempted to take, you will most likely have to reset that student's score to the state before the test was taken. This is not the same as assigning 0 (zero) to a quiz. Zero is recorded as a score and will not allow the student to retake the quiz. The student attempt needs to be completely erased. To do this you will first need to log on to Blackboard and enter your course. Once you are in your course click on Evaluation and select Grade Center.
In the gradebook, locate the student and the quiz you need to reset for that student. Move the cursor on the score that is showing for the specific student and click on the gray down arrow next to the score.
Click on View Grade Detail.
When you click on the score and new window will open. To reset the attempt, click on the Clear Attempt button on the far right of the line.
Click on OK button.
You will then be able to confirm that the attempt has been cleared, and all the actions done to the grade are shown in the Grade History.