NTFS files can be compressed by simply checking the option in the Advanced Attributes Property dialog.

If a folder is compressed then all new files will inherit the compression attribute. If files exist within a folder when it is compressed, the following dialog appears.

Moved files retain their compression attribute.

Source		Move	Destination
				The folder compression attribute does not affect moved files
	—Compressed	Æ		—Compressed
	—Uncompressed	Æ		—Uncompressed

The compression attribute of a copied file is inherited from the destination folder. The source file's compression attribute does not affect the result.

Source		Copy	Destination
				Compressed
	—	Æ		—Compressed
				Uncompressed
	—	Æ		—Uncompressed

Keyboard Exercise

Experiment by compressing a file and then checking its compression attribute after you copy and move it to compressed and uncompressed folders.