NTFS permissions should always automatically cascade down the folder tree - unfortunately this does not always happen.
USB thumb drives are notorious for this as they are likely to contain files Owned by, and hold permissions for, many different user IDs, from multiple systems.
In order to reset the drive to the current system they are attached to what I have done in the past is ....
- Take ownership of the root of the drive.
- Remove all existing permissions on the root folder.
- Set the new required permissions on the root folder.
- Manually propagate the permissions to the rest of the folder tree.
The facilities for this are found on the advanced tab in the security /permissions tab.
Unfortunately sometimes even this method will fail on some especially complex permissions sets and these may need to be treated as separate sub trees