A Windows 10 fault with file permissions

NTFS is still evolving and changing. I believe that the changes to the handling of inherited permissions has first appeared in Vista and has further evolved in Windows 7. The registry setting in your link dates from XP, so as far as I know it is ignored in newer versions.

To understand what happens when one copies/moves a file, one must first understand the difference between implicit and explicit permissions.

Implicit permissions are inherited from the parent folder, so are stored with the parent folder. They are not stored with the children and therefore are not movable/copiable. In other words, these permissions only apply while the child is in its parent folder, because they come from the parent.

Explicit permissions are given manually to the folder/file and are stored in Access Control Lists (ACL) as NTFS attributes. They can be considered as belonging to the item and may in some cases be moved with it if the target file-system is also NTFS.

Some consequences of this NTFS architecture are :

• When a folder/file is copied, new target entries are created in the NTFS tables of the target folder. Therefore the copied file will lose all explicit permissions, and will only inherit from its new parent folder.
• When a file/folder is moved inside the same volume, its NTFS entry is moved, complete with all contained attributes and permissions. Therefore it will retain all explicit permissions, but will lose its old inherited permissions, gaining instead those of its new parent folder.
• When a folder/file is moved between different volumes, the move is treated as a copy and will retain none of the original permissions. The only difference from copy is by the source being deleted when the copy is complete.
• A file/folder that only has inherited permissions, has no permissions to move. Such an item will always inherit its permissions from the parent folder.
• A folder/file may be marked as non-inheriting permissions from its parent. In that case, all its permissions are stored with it as ACLs, meaning as explicit permissions.

This goes against most established documentation, where it is usually claimed that when a folder/file is moved a inside the same volume, it will retain its original NTFS permissions, both implicit and explicit. This was maybe once true in older versions of Windows, but was verified by myself and by the poster as no longer being the case for implicit permissions in Windows 7 and Windows 10.

For an example of erroneously-documented move rules, see the article How file and folder permissions are handled while moving or copying files on Windows 2008 R2 and Windows 7. This article was the source of my discussion below with the poster, where we discovered together the true rules that govern copy and move in NTFS.