Encrypted Files Cannot Be Compressed

When you view the properties of an encrypted file or folder, you may notice that the files are not compressed even though the volume is set to be compressed. If you choose to compress a file using Windows Explorer interface, you may not be able to do so.

NTFS file compression and file encryption are mutually exclusive because of the way NTFS compression is performed. You can use only one of these options at a time on a file.

NOTE: To change a file that is encrypted to compressed, you must have access to the private key (Recovery agent) associated with that file to decrypt the file before it can be compressed.