In addition to using EFS from the explorer GUI, the CIPHER command is provided to encrypt or display the encryption of folder and files on an NTFS partition.
Notes: If you encrypt a folder, all its' files and sub-folders are encrypted. EFS does not work on on an object that has the System attribute. EFS does not work on on a compressed object.Typing cipher /?, at a command prompt, displays:
Displays or alters the encryption of directories \[files\] on NTFS partitions. CIPHER \[/E | /D\] \[/S:dir\] \[/A\] \[/I\] \[/F\] \[/Q\] \[/H\] \[/K\] \[pathname \[...\]\] /E Encrypts the specified directories. Directories will be marked so that files added afterward will be encrypted. /D Decrypts the specified directories. Directories will be marked so that files added afterward will not be encrypted. /S Performs the specified operation on directories in the given directory and all subdirectories. /A Operation for files as well as directories. The encrypted file could become decrypted when it is modified if the parent directory is not encrypted. It is recommended that you encrypt the file and the parent directory. /I Continues performing the specified operation even after errors have occurred. By default, CIPHER stops when an error is encountered. /F Forces the encryption operation on all specified objects, even those which are already encrypted. Already-encrypted objects are skipped by default. /Q Reports only the most essential information. /H Displays files with the hidden or system attributes. These files are omitted by default. /K Create new file encryption key for the user running CIPHER. If this option is chosen, all the other options will be ignored. pathname Specifies a pattern, file or directory. Used without parameters, CIPHER displays the encryption state of the current directory and any files it contains. You may use multiple directory names and wildcards. You must put spaces between multiple parameters.