I have partition D:, there is folder named Pupils, which is shared and there are set permissions for read for all users and full control for administrator. This folder has 9 subfolders - 1.class, 2.class ...
For subfolders are set same permissions as for parent folder.
Now, if I (as administrator) create folder under 1.class and then have look to security tab, I see that Full Control is for Administrators and SYSTEM. There is also user named Account Unknown, which has different SID for each created folder. SID starts with S-1-5-5-0
Owner of this folder is Administrators
Permissions are not inherited from parent folders.
How can I delete unknown user for creating new folders?