Custom Actions

The Windows Installer provides many built-in actions for performing the installation process. For a list of these actions, see the Standard Actions Reference.

Standard actions are sufficient to execute an installation in most cases. However, there are situations where the developer of an installation package finds it necessary to write a custom action. For example:

• You want to launch an executable during installation that is installed on the user's machine or that is being installed with the application.
• You want to call special functions during an installation that are defined in a dynamic-link library (DLL).
• You want to use functions written in the development languages Microsoft Visual Basic Scripting Edition or Microsoft JScript literal script text during an installation.
• You want to defer the execution of some actions until the time when the installation script is being executed.
• You want to add time and progress information to a ProgressBar control and a TimeRemaining Text control.

The following sections describe custom actions and how to incorporate them into an installation package:

• About Custom Actions
• Using Custom Actions
• Custom Action Reference
• Summary List of All Custom Action Types