ASROCK 939S56-M Manual page 19

3. If you want to delete a disk array you selected, you can highlight the disk
array and then click the Delete button. Then a warning message will
pop up. Pay attention to the warning message. You may click Yes to
delete the selected disk array, or click No to cancel.
4. Next, another message will pop up to tell user the setting of these disks
have been changed and ask whether to restart the computer.