I have a HDD with Capacity as 596GB, Used space 173GB & Free space 423GB. However actual used space is 20GB. there were some files(173-20=153GB) Mysteriously got deleted, however the Space was not released, how is it possible? How can I claim back the free space?
Are you sure that the files were deleted and not became hidden? (What do you see if you enable the "show hidden files and folders" option?)