I have bult a SDI based application using MFC 6.0. I use the CArchive mechanism to read/write data to filse. While a document file is open through my application , if I try to delete the file from the Windows Explorer, the file gets deleted. How can I prevent this from happening? This behaviour is also seen in files opened through WordPad / the VC6 IDE. Files currently open from these apps. can be deleted from the Windows Explorer without even a warning! I dont want to allow this behaviour for files currently opened using my application.