Installation (or setup) of a

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

(including

device driver In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

s and plugins), is the act of making the program ready for

execution Capital punishment, also known as the death penalty and formerly called judicial homicide, is the state-sanctioned killing of a person as punishment for actual or supposed misconduct. The sentence ordering that an offender be punished in ...

. Installation refers to the particular configuration of software or hardware with a view to making it usable with the computer. A soft or digital copy of the piece of software (program) is needed to install it. There are different processes of installing a piece of software (program). Because the process varies for each program and each computer, programs (including

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s) often come with an ''installer'', a specialised program responsible for doing whatever is needed (see below) for the installation. Installation may be part of a larger

software deployment Software deployment is all of the activities that make a software system available for use. Deployment can involve activities on the producer (software developer) side or on the consumer ( user) side or both. Deployment to consumers is a hard t ...

process. Installation typically involves files containing program code and data being copied/generated from the installation to new files on the local computer for easier access by the operating system, creating necessary directories, registering

environment variable An environment variable is a user-definable value that can affect the way running processes will behave on a computer. Environment variables are part of the environment in which a process runs. For example, a running process can query the va ...

s, providing a separate program for un-installation etc. Because program files are generally copied/generated in multiple locations, uninstallation usually involves more than just erasing the program folder. For example, registry files and other system code may need to be modified or deleted for a complete uninstallation.

Overview

Some computer programs can be executed by simply copying them into a folder stored on a computer and executing them. Other programs are supplied in a form unsuitable for immediate execution and therefore need an installation procedure. Once installed, the program can be executed again and again, without the need to reinstall before each execution. Common operations performed during software installations include: * Making sure that necessary

system requirements To be used efficiently, all computer software needs certain hardware components or other software resources to be present on a computer. These prerequisites are known as (computer) system requirements and are often used as a guideline as opposed ...

are met * Checking for existing versions of the software * Creating or updating program files and folders * Adding configuration data such as

configuration file A configuration file, a.k.a. config file, is a computer file, file that stores computer data, data used to configure a software system such as an application software, application, a server (computing), server or an operating system. Some applic ...

Windows registry The Windows Registry is a hierarchical database that stores low-level settings for the Microsoft Windows operating system and for applications that opt to use the registry. The kernel, device drivers, services, Security Accounts Manager, a ...

entries or

s * Making the software accessible to the user, for instance by creating links, shortcuts or bookmarks * Configuring components that run automatically, such as daemons or

Windows service In Windows NT operating systems, a Windows service is a computer program that operates in the background. It is similar in concept to a Unix daemon. A Windows service must conform to the interface rules and protocols of the Service Control Manag ...

s * Performing

product activation Product activation is a license validation procedure required by some proprietary software programs. Product activation prevents unlimited free use of copied or replicated software. Unactivated software refuses to fully function until it ''determi ...

* Updating the software versions These operations may require some charges or be free of charge. In case of payment, installation costs means the costs connected and relevant to or incurred as a result of installing the drivers or the equipment in the customers' premises. Some installers may attempt to trick users into installing

junkware Malware (a portmanteau of ''malicious software'')Tahir, R. (2018)A study on malware and malware detection techniques . ''International Journal of Education and Management Engineering'', ''8''(2), 20. is any software intentionally designed to caus ...

such as various forms of

adware Adware, often called advertising-supported software by its developers, is software that generates revenue by automatically displaying Online advertising, online advertisements in the user interface or on a screen presented during the installatio ...

, toolbars,

trialware Shareware is a type of proprietary software that is initially shared by the owner for trial use at little or no cost. Often the software has limited functionality or incomplete documentation until the user sends payment to the software developer. ...

or software of partnering companies. To prevent this, extra caution on what exactly is being asked to be installed is needed. The installation of additional software then can simply be skipped or unchecked (this may require the user to use the "custom", "detailed" or "expert" version of the installation procedure).
Such malicious conduct is not necessarily a decision by the software developers or their company but can also be an issue of external installers such as the Download.com installer by CNET.

Zero-install and portable applications

As mentioned earlier, some computer programs need no installation. This was once usual for many programs which run on DOS, the

classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and end ...

, Atari TOS and

AmigaOS AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions ...

. As computing environments grew more complex and fixed

hard drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating hard disk drive platter, pla ...

s replaced

floppy disks A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...

, the need for tangible installation presented itself. For example Commodore released the Installer for

Amiga Amiga is a family of personal computers produced by Commodore International, Commodore from 1985 until the company's bankruptcy in 1994, with production by others afterward. The original model is one of a number of mid-1980s computers with 16-b ...

. The modern applications that can be run without going through formal process of installation and, in particular, do not require modifications of the

, are sometimes referred to as zero-install. Zero-install can be achieved through multiple means: * a standard solution is to collect the application and its components together, copy them to a fixed directory, and run from there. In the case of Windows OS this approach is occasionally referred to as an " xcopy deployment"; * a browser-based approach. The

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

distribution GoboLinux takes a similar approach (each applications gets its own directory structure), but still introduces the side-effects of the traditional Linux installation to maintain the

backward compatibility In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with Input ...

with the standard Linux directory layout. Isolation of the OS from any changes required by the application can also be achieved through the

application virtualization Application virtualization is a software technology that encapsulates computer programs from the underlying operating system on which they are executed. A fully virtualized application is not installed in the traditional sense, although it is sti ...

tools, like VMware ThinApp, Microsoft App-V, InstallFree Bridge. A class of modern applications that do not need installation and are located on a detachable storage device are known as ''

portable application A portable application (portable app), sometimes also called standalone software, is a computer program designed to operate without changing other files or requiring other software to be installed. In this way, it can be easily added to, run, ...

s'', as they may be moved around onto different computers and run. Similarly, there are ''live operating systems'', which do not need installation and can be run directly from a bootable CD, DVD,

USB flash drive A flash drive (also thumb drive, memory stick, and pen drive/pendrive) is a data storage device that includes flash memory with an integrated USB interface. A typical USB drive is removable, rewritable, and smaller than an optical disc, and u ...

or loaded over the network as with

thin client In computer networking, a thin client, sometimes called slim client or lean client, is a simple (low-Computer performance, performance) computer that has been Program optimization, optimized for Remote desktop, establishing a remote connectio ...

s. Examples are

4.0, various

Linux distribution A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is oft ...

MorphOS MorphOS is an AmigaOS-like operating system designed for Power and PowerPC based computers. The core, based on the Quark microkernel, is proprietary, although several libraries and other parts are open source, such as the Ambient desktop. The p ...

or Mac OS versions 1.0 through 9.0. (See

live CD A live CD (also live DVD, live disc, or live operating system) is a complete booting, bootable computer installation including operating system which runs directly from a CD-ROM or similar storage device into a computer's memory, rather than lo ...

and live USB.) Finally,

web application A web application (or web app) is application software that is created with web technologies and runs via a web browser. Web applications emerged during the late 1990s and allowed for the server to dynamically build a response to the request, ...

s, which run inside a

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

, do not need installation.

Types

Custom installation

A custom installation allows the installer to choose to select components or parts that are required to be installed. This is sometimes preferred as opposed to installing the full suite of software components. Some situations that require the need for a custom install might be where only the basic components are required which are smaller in size instead of the full components which may take up too much hard drive space.

Attended installation

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

systems, this is the most common form of installation. An installation process usually needs a user who attend it to make choices, such as accepting or declining an

end-user license agreement An end-user license agreement or EULA () is a legal contract between a software supplier and a customer or end-user. The practice of selling licenses to rather than copies of software predates the recognition of software copyright, which has ...

(EULA), specifying preferences such as the installation location, supplying passwords or assisting in

. In graphical environments, installers that offer a wizard-based interface are common. Attended installers may ask users to help mitigate the errors. For instance, if the disk in which the computer program is being installed was full, the installer may ask the user to specify another target path or clear enough space in the disk. A common misconception is unarchivation, which is not considered an installation action because it does not include user choices, such as accepting or declining EULA.

Silent installation

A "silent installation" is an installation that does not display messages or windows during its progress. "Silent installation" is not the same as "unattended installation" (see below): All silent installations are unattended but not all unattended installations are silent. The reason behind a silent installation may be convenience or subterfuge.

Malware Malware (a portmanteau of ''malicious software'')Tahir, R. (2018)A study on malware and malware detection techniques . ''International Journal of Education and Management Engineering'', ''8''(2), 20. is any software intentionally designed to caus ...

and viruses can be installed silently when a person clicks on a link while working at a business they think is real but is a hacker's program download. For normal users silent installation is not of much use, but in bigger organizations where thousands of users work, deploying the applications becomes a typical task and for that reason silent installation is performed so that the application is installed in the background without affecting the work of the user. Silent parameters can vary from software to software; if a software/application has silent parameters, it can be checked by " /? " or " /help " or " -help ". Silently installing a software program can be used to deploy a program on networks in educational institutions, including

primary Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Work ...

and

secondary education Secondary education is the education level following primary education and preceding tertiary education. Level 2 or ''lower secondary education'' (less commonly ''junior secondary education'') is considered the second and final phase of basic e ...

and universities, in addition to business, government, and corporate networks. The person managing the silent installation can choose to add a desktop shortcut, for example, to silently install Google Drive with a desktop shortcut: GoogleDrive.exe --silent --desktop_shortcut=true

Unattended installation

Installation that is performed without user interaction during its progress or with no user present at all. One of the reasons to use this approach is to automate the installation of a large number of systems. An unattended installation either does not require the user to supply anything or has received all necessary input prior to the start of installation. Such input may be in the form of

command line A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

switches or an ''answer file'', a file that contains all the necessary parameters.

Windows XP Windows XP is a major release of Microsoft's Windows NT operating system. It was released to manufacturing on August 24, 2001, and later to retail on October 25, 2001. It is a direct successor to Windows 2000 for high-end and business users a ...

and most Linux distributions are examples of operating systems that can be installed with an answer file. In unattended installation, it is assumed that there is no user to help mitigate errors. For instance, if the installation medium was faulty, the installer should fail the installation, as there is no user to fix the fault or replace the medium. Unattended installers may record errors in a computer log for later review.

Headless installation

Installation performed without using a

computer monitor A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a electronic visual display, visual display, support electronics, power supply, Housing (engineering), housing, electri ...

connected. In attended forms of headless installation, another machine connects to the target machine (for instance, via a

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...

) and takes over the display output. Since a headless installation does not need a user at the location of the target computer, unattended headless installers may be used to install a program on multiple machines at the same time.

Scheduled or automated installation

An installation process that runs on a preset time or when a predefined condition transpires, as opposed to an installation process that starts explicitly on a user's command. For instance, a

system administrator An IT administrator, system administrator, sysadmin, or admin is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems, especially multi-user computers, such as Server (computing), servers. The ...

willing to install a later version of a computer program that is being used can schedule that installation to occur when that program is not running. An operating system may automatically install a device driver for a device that the user connects. (See

plug and play In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving reso ...

.) Malware may also be installed automatically. For example, the infamous Con ficker was installed when the user plugged an infected device to their computer.

Clean installation

A clean installation is one that is done in the absence of any interfering elements such as old versions of the computer program being installed or leftovers from a previous installation. In particular, the clean installation of an operating system is an installation in which the target

disk partition Disk partitioning or disk slicing is the creation of one or more regions on Computer data storage#Secondary storage, secondary storage, so that each region can be managed separately. These regions are called partitions. It is typically the first ...

is erased before installation. Since the interfering elements are absent, a clean installation may succeed where an unclean installation may fail or may take significantly longer.

Network installation

Network installation, shortened net install, is an installation of a program from a shared network resource that may be done by installing a minimal system before proceeding to download further packages over the network. This may simply be a copy of the original media but software publishers which offer site licenses for institutional customers may provide a version intended for installation over a network.

Installer

An ''installation program'' or ''installer'' is a

that installs files, such as

applications Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a ...

, drivers, or other

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

, onto a computer. Some installers are specifically made to install the files they contain; other installers are general-purpose and work by reading the contents of the software package to be installed. They exist both as "standalone installer" (or "offline installer") & "web installer" (or "online installer"), where the former allows for

offline In computer technology and telecommunications, online indicates a state of connectivity, and offline indicates a disconnected state. In modern terminology, this usually refers to an Internet connection, but (especially when expressed as "on li ...

installation as it contains all installation files, whereas the latter needs to download files necessary for installation from the web at the time of installation. The differences between a

package management system A package manager or package management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals wi ...

and an installer are:

Bootstrapper

During an installation of a

, it is sometimes necessary to update the installer or

package manager A package manager or package management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner. A package manager deals wi ...

itself. To make this possible, a technique called

bootstrapping In general, bootstrapping usually refers to a self-starting process that is supposed to continue or grow without external input. Many analytical techniques are often called bootstrap methods in reference to their self-starting or self-supporting ...

is used. The common pattern for this is to use small executable files which update the installer and starts the real installation after the update. This small

executable In computer science, executable code, an executable file, or an executable program, sometimes simply referred to as an executable or binary, causes a computer "to perform indicated tasks according to encoded instruction (computer science), in ...

is called bootstrapper. Sometimes the bootstrapper installs other prerequisites for the

during the bootstrapping process too.

Common types

Cross-platform installer builders produce installers that run on Windows,

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

and

. An example is InstallAnywhere by Flexera Software, which is based on

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

. An instance of native code is InstallAware Multi Platform by InstallAware Software, featuring build toolchains and a setup engine that runs without dependencies; it can also switch to console mode if a

graphical user interface A graphical user interface, or GUI, is a form of user interface that allows user (computing), users to human–computer interaction, interact with electronic devices through Graphics, graphical icon (computing), icons and visual indicators such ...

(GUI) cannot be displayed on Linux.

Windows NT family Windows NT is a proprietary graphical operating system produced by Microsoft as part of its Windows product line, the first version of which, Windows NT 3.1, was released on July 27, 1993. Originally made for the workstation, office, and ser ...

includes an installation

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

and an associated service called

Windows Installer Windows Installer (msiexec.exe, previously known as Microsoft Installer, List of Microsoft codenames, codename Darwin) is a software component and application programming interface (API) of Microsoft Windows used for the Installation (computer ...

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

provides a minimum level of tools required to create installers using Windows Installer in the freely available Windows SDK, instead focusing on the API to allow developers and third parties to leverage it in creating custom installers. Third-party tools may supporting create installers using this API to speed the process. Examples include

InstallShield InstallShield is a proprietary software tool for creating installers or software packages. InstallShield is primarily used for installing software for Microsoft Windows desktop and server platforms, though it can also be used to manage software ...

( Flexera Software) and WiX ( Outercurve Foundation). Installation authoring tools that do not rely on Windows Installer include Wise Installation Studio ( Wise Solutions, Inc.), Installer VISE (MindVision Software), Visual Installer (SamLogic), NSIS, Clickteam, InnoSetup and InstallSimple. InstallAware for Windows Installer features a hybrid installation engine, whereby a setup may be executed using either the Windows Installer APIs, or directly through InstallAware's native code setup engine. This hybrid engine also provides the capability to switch installation modes at runtime. macOS includes Installer, a native

. macOS also includes a separate software updating application, Software Update, that only supports Apple and system software. Included in the

Dock The word dock () in American English refers to one or a group of human-made structures that are involved in the handling of boats or ships (usually on or near a shore). In British English, the term is not used the same way as in American Engl ...

as of 10.6.6, and also in the Apple menu, the

Mac App Store The Mac App Store (also known as the App Store) is a digital distribution platform for macOS apps, often referred to as Mac apps, created and maintained by Apple. The platform was announced on October 20, 2010, at Apple's "Back to the Mac" eve ...

shares many attributes with the successful

App Store An app store, also called an app marketplace or app catalog, is a type of digital distribution platform for computer software called applications, often in a mobile context. Apps provide a specific set of functions which, by definition, do not i ...

for iOS devices, such as a similar app approval process, the use of Apple ID for purchases, and automatic installation and updating. Although the App Store is Apple's preferred delivery method for macOS apps, previously purchased licenses cannot be transferred to the Mac App Store for downloading or automatic updating. Instead of an installer, many macOS applications distributed outside the Mac App Store use an

Apple Disk Image Apple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Finder. An Apple Disk Image can be structured according to one of several proprietary disk ...

(.dmg file) that contains an application bundle to be dragged and dropped into the Applications folder; those applications are described as drag-install applications. These often feature prominent installation instructions and a shortcut to the Applications folder; that style of drag-install application was invented and published by Iris Artin (formerly Ben Artin) during the development of Fetch 5 and subsequently gained wide adoption. Commercial applications for macOS may also use a third-party installer, such as the Mac version of Installer VISE (MindVision Software) or InstallerMaker ( StuffIt).

System installer

A ''system installer'' is the software that is used to set up and install an operating system onto a device. Windows Setup is the system installer of Microsoft Windows. Examples of Linux system installers: * Anaconda: used by

CentOS CentOS (, from Community Enterprise Operating System; also known as CentOS Linux) is a discontinued Linux distribution that provided a free and open-source community-supported computing platform, functionally compatible with its upstream (softw ...

, Fedora * Calamares: used by multiple Linux distributions (incl. some Ubuntu flavors, Debian, and derivates) * Debian-Installer ("D-I"): classic

Debian Debian () is a free and open-source software, free and open source Linux distribution, developed by the Debian Project, which was established by Ian Murdock in August 1993. Debian is one of the oldest operating systems based on the Linux kerne ...

installer (textual and graphicalDebian Wiki: Debian Installer GUI
/ref> interfaces)
Subiquity
Ubuntu Server installer * Ubiquity:

Ubuntu Ubuntu ( ) is a Linux distribution based on Debian and composed primarily of free and open-source software. Developed by the British company Canonical (company), Canonical and a community of contributors under a Meritocracy, meritocratic gover ...

Desktop installer (until 22.10)
Ubuntu Desktop Installer
current

Desktop installer (starting 23.04) * YaST for SUSE-based projects Another example is found in the

Haiku is a type of short form poetry that originated in Japan. Traditional Japanese haiku consist of three phrases composed of 17 Mora (linguistics), morae (called ''On (Japanese prosody), on'' in Japanese) in a 5, 7, 5 pattern; that include a ''kire ...

operating system, which uses a utility called Haiku Installer to install itself onto a device after booting from a

or live USB.

References

Sources

* * * {{Authority control