ReadDirectoryChangesW() - Retrieves information that describes the changes within the specified directory. The function does not report changes to the specified directory itself.
To track changes on a volume, see change journals.
References:
Obtaining Directory Change Notifications -
http://msdn.microsoft.com/en-us/library/aa365261(VS.85).aspx
http://msdn.microsoft.com/en-us/library/aa365465(VS.85).aspx
http://www.codeproject.com/KB/files/directorychangewatcher.aspx
PRB: ReadDirectoryChangesW Not Giving Consistent Notification -
http://support.microsoft.com/kb/245214