Installation and uninstallation

Installing a new piece of software is something that beginners often have to do. Therefore it must be easy.

The installation procedure should be standardized so that it works the same way for all programs. Preferably, the installation procedure should be part of the operating system. If such a feature doesn't exist as part of the operating system then use a standard software tool. Most software packages use Installshield which gives the installation procedure a well-known interface and takes care of the operating system tasks in a standardized way. A further advantage is that it can install the software from a single installation file. This is useful when the software can be downloaded from the Internet. Let the user download an installation file and execute it, rather than making an online installation procedure, because the latter method may give unpredictable problems if the connection is interrupted while installing or if the download takes longer time than the user can accept.

All files belonging to a particular program should be stored in the same directory or its subdirectories so that the user knows which files belong to which program. Avoid very deep directory structures.

Installation procedures often have options about which components to install. This should include a help facility that gives a full explanation of the purpose of each component so that the user can make an informed decision.

Installation programs often ask questions of the type: "Do you want to replace version X of this file with version Y?". Some installation program keep asking this kind of questions with unpredictable intervals all through the installation procedure, which may last for a full hour or more. The program should rather ask all questions at the beginning so that the user can take a break or do something else while the installation finishes.

Uninstalling a program can be much more difficult than installing it. It is quite common for several programs to share the same files. Such shared files can of course only be deleted when all programs using them are uninstalled. The only way of keeping track of which files are used by which programs is to store this information in a database maintained by the operating system. Programs using shared files must comply with the standards of the operating system for storing such information.

Some programs ask you to insert the original distribution CD when you want to uninstall. But what if the original disc has been misplaced, lost or damaged? Then you cannot uninstall the program. This is certainly unacceptable. A proper uninstallation procedure should rely solely on the operating system, and all installation programs should comply with the standards of the operating system for enabling easy uninstallation. Unfortunately, not all operating systems have this feature.

This page was last modified 2008-Dec-08