What is a self-extracting file? A self-extracting file typically contains other  files that first have been compressed (most commonly ZIPped) then appended to with a Windows executable  (called a stub).   The result is sometimes referred to as an archive, extract or executable ZIP file which can then be sent as a file attachment, placed on an FTP to download or copied to magnetic media (e.g. a CD-ROM) and which can be executed or "run" by the end user without the need for any other software.  This is usually the most efficient way to distribute multiple files whether on a diskette or a file download because multiple files are combined into one and are further physically reduced in size to take up the least amount of space or bandwidth as possible; this also greatly simplifies the process of software installation and updates for end users.

Should I make any back-ups first? The self-extracting file may contain files that overwrite existing files. Typically this will NEVER involve any data files, normally only program files (e.g. with EXE or RUN extensions). So the chance of any data loss should normally be essentially zero. On the splash screen when installing the self-extracting file you may be told what files are being replaced or what files to back-up as a precaution. You may wish to make a complete copy of the subdirectory to which the files are being extracted to as an extreme precaution. This is normally best handled by making a quick copy of the affected subdirectory into a temporary directory on your local hard drive.

Should other users be in the system when installing? As a general rule, yes, all other users should be out of the software (including you!) while installing to avoid open file conflicts which could prevent some files from being extracted and therefore being updated.

Do I need to close other running software on my PC while running the self-extracting file? Not necessarily, just the software that the self-extracting file pertains to if it is a software update.  Sometimes however self-extracting files in turn run a setup program which may install system files and make registry changes.  In that event, it is a good idea to exit out of all other software..

How do I start installing the self-extracting file? Unless you have received the file on a diskette, first save the self-extracting file using your E-mail or Internet browsing software somewhere on your hard drive or to a floppy diskette. (NOTE: as a general rule, avoid saving files to your DESKTOP subdirectory, e.g. C:\WINDOWS\DESKTOP on 95/98 PC's or in your "Documents and Settings" Desktop folder in WIN 2000.) This could be the actual subdirectory (folder) where the file will be installed or in a temporary subdirectory such as C:\TEMP or in a DOWNLOADS subdirectory. Your E-mail or browser may also allow you to OPEN the attachment or download directly without your having to run/execute it; otherwise run it by browsing to it (right click on START then EXPLORE or left click on START then RUN and then Browse); or if you know the path/filename, click on START then RUN and type in the file name and click on OK (for this reason it is helpful to note what the path and name of the file is in the event that you want to avoid hunting for it). Example: you saved a file called UPDATE.EXE into your C:\TEMP directory, click on START then RUN then next to "Open:" type C:\TEMP\UPDATE.EXE and click on OK. If received on a diskette, just make sure that the diskette is fully inserted and then click on START then RUN and next to "Open:" type A:\UPDATE.EXE (if that is the name of the file) or click on Browse and click on the file name on the floppy drive to select it.

How do I then complete the installation? Note any special comments or instructions on the splash screen including the intended version that the file applies to if any and click on Next. Verify that the file extraction path is correct. A default may be provided but this may very well NOT be the location of the software on your system (is this is an update to previously installed software). The default drive letter will likely be "C:" but that might only be appropriate if you are running on the actual server or host; otherwise the correct drive letter might be something like F: or N: or some other letter. Further the subdirectory/folder name may also not be the one being used on your system. If in doubt you can use the Browse option or minimize the self-extraction program and if you have a desktop icon which points to the application, right click on it and inspect the Properties (Shortcut or General tabs) which should reveal the path. When you have verified the path, click on Next and the files will be extracted. In some cases, the self-extracting file may also run an additional program that also needs to be run and in connection with which you may need to respond to additional prompts (if that is the case and the program designated to run cannot be run, you may receive an error message and the self-extracting program will delete the files that it just extracted).

Should the extract file itself be deleted after installation has occurred? As a general rule, yes. And to avoid cluttering your actual installation directory, files downloaded via E-mail or through the Internet should be placed in temporary subdirectories. The self-extracting file generally has no way to delete itself once installation has occurred, and normally it is a good idea to delete it to prevent it from being run again in the future and possibly overwriting more current program files as well as to reduce clutter. Deleting can be accomplished through the Windows Explorer or at the DOS prompt, e.g. DEL C:\TEMP\UPDATE.EXE.

What if I receive an error message indicating that the files could not be extracted or a directory could not be created?  The most common reason for this is that one or more files relating to what you are installing are open.  Make sure that the application you are installing to is not in use by you (nor by others if a network application).  In a severe situation where the operating system "thinks" that the files are still open, you may need to shutdown your PC and the PC that is the host or server of the application (if any).    If you are installing an update and the files you are trying to overwrite have been marked as read-only you may need to remove the read-only attribute (e.g. ATTRIB -R FILENAME at a command prompt or using Windows Explorer).  (Normally program files are not marked read-only.) If you get an error message indicating that the self-extracting program could not create the directory (typically in connection with new installations), it could be that a file with the same name as that directory name exists in the subdirectory path that you are trying to install.  Either rename the conflicting file to something else (assuming that won't create some other problem) or change the path name that you are installing to.