g Folders</h2><p>
The internal drag drop sample uses the code from the Shell samples also in this section
to populate a TreeView with file system folders.  Adding drag capability involves three
things:
</p><ol><li>Preventing dragging of items which can't be moved (the root items in the folder tree).</li><li>Validating the drag location of the folder to prevent it from being made a child of itself
or an illegal location.</li><li>Actually moving the item when it is dropped.</li></ol><p>
The first point is cov