To compress a file or folder on an NTFS drive
Open My Computer
Double-click a drive or folder.
Right-click the file or folder you want to compress, and then click Properties.
On the General tab, click Advanced.
Select the Compress contents to save disk space check box, and then click OK.
In the Properties dialog box, click OK.
In Confirm Attribute Changes, select the option you want.
To open My Computer, click Start, and then click My Computer.
You can only use NTFS compression for files and folders on drives formatted as NTFS If the Advanced button does not appear, the file or folder you selected is not on an NTFS drive.
If you move or copy a file into a compressed folder, it is compressed automatically. If you move a file from a different NTFS drive into a compressed folder, it is also compressed. However, if you move a file from the same NTFS drive into a compressed folder, the file retains its original state, either compressed or uncompressed.
Files and folders that are compressed using NTFS compression cannot be encrypted.
You can choose to display NTFS-compressed files in a different color. For more information, click Related Topics.