Explanation/Reference:
To change a dynamic disk back to a basic disk using the Windows interface
1. Back up all volumes on the disk you want to convert from dynamic to basic.
2. In Disk Management, right-click each volume on the dynamic disk you want to convert to a basic disk, and then click Delete Volume for each volume on the disk.
3. When all volumes on the disk have been deleted, right-click the disk, and then click Convert to Basic Disk.