File compression overview

Compressing files, folders, and programs decreases their size and reduces the amount of space they use on your drives or removable storage devices. Drive compression decreases the amount of space used by all of the files and folders stored on that drive.

Windows supports two types of compression: NTFS compression and compression using the Compressed (zipped) Folders feature.

NTFS compression versus Compressed (zipped) Folders

NTFS compression

If you do not have an NTFS drive, this option is not available. To determine whether your drive is formatted with NTFS, open My Computer, right-click a drive, and then click Properties. The file system is indicated on the General tab. In the illustration below, the Hard Disk file structure is seen to be FAT32 (i.e. not NTFS).

You can compress individual files and folders using NTFS compression, as well as entire NTFS drives. It is also worth noting that you can compress a folder without compressing its contents. After compression, you can work with NTFS-compressed files without decompressing them. NTFS-compressed file and folder names can be displayed in a different color to make them easier to identify.

You may notice a decrease in performance when working with NTFS-compressed files. When you open a compressed file, Windows automatically decompresses it for you, and when you close the file, Windows compresses it again. This process may decrease your computer’s performance. NTFS-compressed files and folders only remain compressed while they are stored on an NTFS drive. You cannot encrypt an NTFS-compressed file.

Note: NTFS file encryption is not available on Windows XP Home Edition.

Compressed (zipped) Folders

• Files and folders that are compressed using the Compressed (zipped) Folders feature remain compressed on both FAT and NTFS drives.
• You can run some programs directly from these compressed folders without decompressing them. You can also open files directly from compressed folders.
• Zipped compressed files and folders can be moved to any drive or folder on your computer, the Internet, or your network, and they are compatible with other file compression programs.
• Folders compressed using this feature are identified by a zipper icon.
• You can protect files in a zipped compressed folder with a password.
• Compressing folders using Compressed (zipped) Folders will not decrease your computer's performance.
• To compress individual files using Compressed (zipped) Folders, create a compressed folder and then move or copy the files to that folder.

• To open My Computer, double-click the My Computer icon on the desktop.
• The Compressed (zipped) Folders feature is not available on Windows XP 64-Bit Edition.

Compressing a File or Folder on an NTFS Drive To compress a file or folder on an NTFS drive

1. Open My Computer.
2. Double-click a drive or folder.
3. Right-click the file or folder you want to compress, and then click Properties.
4. On the General tab, click Advanced.
5. Select the Compress contents to save disk space check box, and then click OK.
6. In the Properties dialog box, click OK.
7. In Confirm Attribute Changes, select the option you want.

Notes

• To open My Computer, double-click the My Computer icon on the desktop.
• 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.

Compressing an NTFS Drive To compress an NTFS drive

You must be logged on as a computer administrator in order to complete this procedure.

1. Open My Computer.
2. Right-click the drive you want to compress.
3. Click Properties.
4. On the General tab, select the Compress drive to save disk space check box, and then click OK.
5. In Confirm Attribute Changes, select the option you want.

Note

• To open My Computer, double-click the My Computer icon on the desktop.

To configure data compression

1. In the Remote Desktop Connection window, click Options.
2. On the Advanced tab, verify that the Use compression check box is selected. Or, to disable compression, click the Use compression check box to clear it.
3. Click Connect.

Notes

• To open Remote Desktop Connection, click Start, point to Programs or All Programs, point to Accessories, point to Communications, and then click Remote Desktop Connection.
• By default, compression is enabled for Remote Desktop connections. Compression reduces the amount of data that has to be sent across the network, but it requires a small amount of extra processing power. If your processor is slow, you might try disabling compression. However, it is recommended that you use compression unless instructed otherwise by your network administrator.

When you click Connect, the information you have entered in Options becomes the default setting for all Remote Desktop connections and is saved in a file called Default.rdp.