Windows 7 no longer places
thumbs.db files in the directories containing media files. However, it still does this on access, copy or move of media files from or to shared network directories.
To stop such creation of
Open the Group Policy Editor with Administrator privileges. The easiest way to do this is by typing
gpedit.msc at the Start menu.
In the Group Policy Editor dialog, drill down to User Configuration → Administrative Templates → Windows Components → Windows Explorer → Turn off the caching of thumbnails in hidden thumbs.db files.
Right-click on this item, edit it and make it enabled.
Tried with: Windows 7