The DragAcceptFiles function registers whether a window accepts dropped files.
VOID DragAcceptFiles(
| HWND hWnd, | // handle to the registering window | 
| BOOL fAccept | // acceptance option | 
| ); | 
This function does not return a value.
An application that calls DragAcceptFiles with the fAccept parameter set to TRUE has identified itself as able to process the WM_DROPFILES message from File Manager.