App Installer is a

software component Component-based software engineering (CBSE), also called component-based development (CBD), is a branch of software engineering that emphasizes the separation of concerns with respect to the wide-ranging functionality available throughout a give ...

Windows 10 Windows 10 is a major release of Microsoft's Windows NT operating system. It is the direct successor to Windows 8.1, which was released nearly two years earlier. It was released to manufacturing on July 15, 2015, and later to retail on J ...

, introduced in the 2016

Anniversary Update Windows 10 Anniversary Update (also known as version 1607 and codenamed "Redstone 1") is the second major update to Windows 10 and the first in a series of updates under the Redstone codenames. It carries the build number 10.0.14393. This update, ...

, used for the installation and maintenance of applications packaged in .appx or .appxbundle installation packages; they are loosely

relational databases A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...

with an

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...

app manifest. The .appx and .appxbundle files contain either a

Win32 The Windows API, informally WinAPI, is Microsoft's core set of application programming interfaces (APIs) available in the Microsoft Windows operating systems. The name Windows API collectively refers to several different platform implementations th ...

or a

Universal Windows Platform Universal Windows Platform (UWP) is a computing platform created by Microsoft and first introduced in Windows 10. The purpose of this platform is to help develop universal apps that run on Windows 10, Windows 10 Mobile (discontinued), Windo ...

app, icons for the

Start menu The Start menu is a graphical user interface element used in Microsoft Windows since Windows 95 and in other operating systems. It provides a central launching point for computer programs and performing other tasks in the Windows shell. It is name ...

and taskbar, a virtualized version of any

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, and ...

keys needed, and any other assets needed for the installed app to function. The only other Windows components capable of installing APPX packages are

Windows Store Microsoft Store (formerly known as Windows Store) is a digital distribution platform operated by Microsoft. It started as an app store for Windows 8 and Windows Server 2012 as the primary means of distributing Universal Windows Platform app ...

and

Windows PowerShell PowerShell is a task automation and configuration management program from Microsoft, consisting of a command-line shell and the associated scripting language. Initially a Windows component only, known as Windows PowerShell, it was made open-so ...

. However, the latter requires Developer Mode to be turned on. App Installer provides a more user-friendly interface that is opened by clicking on the installation package. The design for App Installer is similar to the one for the classic

Windows Installer Windows Installer (msiexec.exe, previously known as Microsoft Installer, codename Darwin) is a software component and application programming interface (API) of Microsoft Windows used for the installation, maintenance, and removal of software. ...

, which installs stand-alone MSI files. It shows the app name, the developer, the Start menu tile, and a set of capabilities enabled by the app manifest. If the user clicks the Install button at the bottom right corner, the App Installer checks the app's

digital certificate In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the validity of a public key. The certificate includes information about the key, information about the ...

. Unlike a standalone installer, App Installer refuses to install an app without a valid digital certificate. If the certificate is valid, the app displays a blue installation progress bar. It shows the user a button to launch the app once it is fully installed. App Installer is physically more flexible than Windows Installer. It can be resized and viewed in full-screen mode and the background changes based on the system-wide light or

dark mode A light-on-dark color scheme —also called black mode, dark mode, dark theme, night mode, or lights-out (mode)— is a color scheme that uses light-colored text, icons, and graphical user interface elements on a dark background. It is often ...

. Apps installed with App Installer can be updated through the Windows Store. It is also possible to update an app with an App Installer by opening the package with a higher version number than the one installed. Since APPX installations are sandboxed, unlike traditional software, running multiple installations at once is possible. MSIX packages are designed to have a stable installation progress. Along with the ability to uninstall, MSIX packages share files across the system to save space. The packages are currently supported for installations and updates across Windows

Desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

Server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

, and

Enterprise Enterprise (or the archaic spelling Enterprize) may refer to: Business and economics Brands and enterprises * Enterprise GP Holdings, an energy holding company * Enterprise plc, a UK civil engineering and maintenance company * Enterpris ...

. These packages can be entirely self-contained or fetch files from a remote location to complete the install. All distributed apps are required to be signed by a key from a trusted

Certificate Authority In cryptography, a certificate authority or certification authority (CA) is an entity that stores, signs, and issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate. Thi ...

References

Installation software Windows components Windows administration {{Windows-stub