Reference number: CH000506

How do I extract or uncompress a compressed file?

Question:

How do I extract or uncompress a compressed file?

Answer:

Before extracting the data from the compressed file you must first determine the type of compressed file. Commonly, this is performed on IBM compatible computers by the file extension. Commonly, the vast majority of compressed files are ".ZIP", ".RAR", "TAR.GZ", and ".TGZ" files. Below are some examples of what some of the different compressed icons look like in Microsoft Windows.

Once the type of compressed file has been determined, a user can then use the appropriate program. For example, if the compressed file is a ZIP file, a user could use WinZip, Pkzip, or any other Compression utility to extract the contents of the file. If the compressed file is RAR, a user could use WinRAR to extract the files. Each of these utilities can be downloaded through our recommended download section. If you are using Microsoft Windows XP, your computer should already be cable of extracting the contents of ZIP files.

Once a compression program has been installed on the computer, a user should be able to extract the contents from the compressed file. Below are some basic steps on how you can extract files.

Note: Windows XP users should not need to download a third-party compression utility unless they wish to.

MS-DOS users

MS-DOS users will need to extract the files using the command line. We recommend users use the pkzip and pkunzip utilities to compress and uncompress their files. Additional help and information about how files can be extracted from the command line can be found on our PKZIP and PKUNZIP page. 

Microsoft Windows 95, 98, ME, NT, 2000, and XP users

In Microsoft Windows, locate the compressed file and right-click the file. This should open a menu that gives you the options to 'Extract' or Extract all' the file. Click one of these options to extract the file. This should open a program with additional options such as the location to where you wish to extract the files to.

WARNING: When extracting the files, pay close attention to where you are extracting the files. Extracting the files to the incorrect location such as the desktop can cause a lot of havoc.

• If you are attempting to extract the file from an e-mail, you may need to save the file to an alternate location such as a folder on your hard disk drive before it can be extracted.
• If after extracting the files you need help installing the software program, we recommend your see document CH000561.

Linux / Unix users

Unlike many other operating systems, almost all variants of Linux and Unix come pre-installed with some form of command capable of compressing and uncompressing files. Linux and Unix users are likely to be dealing with file extensions such as ".TAR", "TGZ", ".Z" or ".TAR.GZ". See the below Linux and Unix command pages for additional information about the commands used to create compressed files and to uncompress files.

gunzip
pack
tar
uncompress
zcat

Additional information:

• Additional information about how to compress a file can be found on document CH000808.
• A dictionary definition of "compress" and related terms can be found here.
• A listing of computer compression programs can be download here.
• A listing of computer file extensions can be found here.

Users attempting to use the extract command to extract windows files from the Microsoft Windows cabinets should refer to CH000363.