Consider the following scenario. In Windows Vista, you use Encrypting File System (EFS) to create an EFS-encrypted file. Or, you edit an EFS-encrypted file in Windows Vista. Then, you try to open the file in Microsoft Windows XP or in Microsoft Windows Server 2003. In this scenario, you receive an error message that resembles the following:

Access is denied

You cannot open an EFS-encrypted file in Windows XP or in Windows Server 2003 after the file has been opened in Windows Vista.