Uff! First, I thought the problem, that Defraggler cannot handle as a folder mounted partitions, was never reported before. Now I see that this problem is known since 2008 (!!!). Until right now I cannot see that Defraggler has a solution for this OS feature. I have, like the two members before, hard drives, which were mounted in a empty folder. In Defraggler I can see the drive with the folder inside in which these drives are mounted but I cannot defrag this drives because Defraggler doesn't recognize the folders and files on the mounted hard drives. So the question is: How can I defrag drives mounted like this with Defraggler. By the way: O&O's defrag software CAN defrag such drives and shows them correctly for example like D:\MyFiles\MountedFolder\DriveOne !!!