file extension MSI

Microsoft Windows Installer is an installation and configuration service that reduces the total cost of ownership. The Installer ships with Windows Vista, the Windows Server 2003 family, Windows XP, and Windows 2000.

Windows Installer enables customers to provide better corporate deployment and provides a standard format for component management. The installer supports the advertisement of applications and features according to the operating system.

Not all the capabilities available in later Windows Installer versions are available in earlier versions.

Beginning with Windows Installer 3.0, multiple patches can be installed with a single transaction that integrates installation progress, rollback, and reboots. The installer can apply patches in a constant order regardless of the order that the patches are provided to the system.

Patches installed with Windows Installer 3.0 or later can be uninstalled in any order to leave the state of the product the same as if the patch was never installed. Patching using Windows Installer 3.0 only updates files affected by the patch and can be significantly faster than earlier installer versions.

Accounts with administrator privileges can use Windows Installer 3.0 functions to query and inventory product, feature, component, and patch information; and to read, edit, and replace Installer source lists for network, URL, and media sources. Administrators can enumerate across user and install contexts, and manage source lists from an external process.

Installation packages and patches that are created for Windows Installer 2.0 can be installed by using Windows Installer 3.0.

Where Applicable

Windows Installer enables the efficient installation and configuration of your products and applications. The installer provides new capabilities to advertise features without installing them, to install products on demand, and to add user customizations.