dir /s /q /f /a:h Thumbs.db

del /s /q /f /a:h Thumbs.db

List all Files (also in subdirectories) with Hidden Attribute dir /S /A:h
List all Files (also in subdirectories) with System Attribute dir /S /A:s

Delete all ** files : del /s /q /f /a:h desktop.ini or del /s /q /f /a:h thumbs.db