The New Microsoft Windows Installer

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The new Microsoft^® Windows^® installer reduces the total cost of ownership (TCO) for your customers by enabling them to efficiently install and configure your products and applications. The new Windows installer is part of the Windows 2000 and Zero Administration Windows (ZAW) efforts to reduce the overall cost of deploying, using, and managing desktop computers.

The installer is also available for Windows 95, Windows 98, Microsoft^® Windows NT^® 4.0, and later platforms. Windows installer-based setups can run on any 32-bit Windows platform.

Microsoft^® Visual Studio^® Installer is a tool you can use to build and package Windows installer-based setups to distribute to single or enterprise-wide users. With Visual Studio Installer, you can take advantage of all the benefits provided with the new Windows installer, while working in the Microsoft development environment.

Note   For specific information about how Visual Studio Installer supports Windows installer-based setups, see Visual Studio Installer and the Microsoft Windows Installer in Considerations for Choosing Visual Studio Installer.

Background information about the Windows installer includes:

• The concept of data-driven installations.
  
  
• Benefits for authors of Windows installer packages.
  
  
• Benefits for users of Windows installer packages.

Data-Driven Installation

The new Windows installer is based on a data-driven model and provides all installation data and instructions in a single, complete package. In contrast, traditional scripted setup programs were based on a procedural model, providing scripted instructions for application installations. The new data-driven installation model provides several benefits for developers and users of Windows-installer based setups, including:

• Faster and easier application installations.
  
  
• On-demand feature installation.
  
  
• Application self-repair.
  
  
• Powerful installation rollback capabilities.

Data-Driven vs. Script-Based Installation

With traditional script-based installations, every installation program provided a set of instructions for a specific application installation. Though these hard-coded sequenced instructions may have worked fine for a single installation, they could cause problems if new applications or versions were subsequently installed, uninstalled, or reinstalled. Also, since information was not shared among setup scripts, it was difficult for users or administrators to track and manage installed applications.

The new, data-based Windows installer addresses many of the problems associated with installation scripts. In the data-driven installation model, you create a master set of installation tables where every application resource (files, registry keys, and so on) is clearly tied to the component or feature it supports. In creating these tables, you concentrate on what you're installing, rather than how you install it. You focus on the objects to install and where to install them, and the Windows installer manages the procedural instructions.

Benefits for Authors of Windows Installer Packages

When you write installation packages based on the Windows installer, you gain:

• Ease of use. It's easier to write an installer package based on what is installed rather than on instructions about how to install it.
  
  
• Centralized maintenance and updates. You control all application and installation configurations from your central data set. Keeping all application information in this central location, rather than maintaining multiple copies of the information, makes it easier for you to maintain and distribute installations and upgrades.

Benefits for Users of Windows Installer Packages

Most importantly, Windows installer packages make application installations easier for your users. Windows installer packages can run on any 32-bit Windows 95, Windows 98, Windows NT 4.0, or Windows 2000 platforms. Users working on machines that meet these minimum requirements realize many benefits from Windows installer packages, including:

• Faster and easier application installations. Because all the installation information about an application is maintained in a central location, you can predetermine the answers to many installation questions, reducing the occasions for your users to make complex decisions when they install or update the application. Once a user has made their selections, the installer can install the selected configuration with just one pass through the data.
  
  
• On-demand feature installation. Information about uninstalled features is also maintained in a central location. This means if your user at some point wants to use a feature they didn't install with your application, they won't have to rerun the entire installation package just to add that feature. When your user requests the feature, the application simply checks the installation data and retrieves the necessary information, adding the desired functionality on demand.
  
  
• Application self-repair. Because the centralized installation information enables your application to repair itself, your users spend less time uninstalling and reinstalling an application, as well as trying to fix undiagnosed or difficult to identify problems. A malfunctioning application can check installation data to discover and replace any missing or corrupt files.
  
  
• Powerful rollback capabilities. The Windows installer maintains an "undo" operation for every change it makes during any installation. If your user encounters a fatal error that stops the install process, the user can still return the machine to its exact pre-installation state. Even if an installation fails, users can continue to be productive with their previous set of applications.

Additional Benefits for Windows 2000 Users

Users running on Windows 2000 can realize additional benefits from the Windows installer, including:

• Application Advertising capabilities.
  
  
• The ability to run installation programs on "locked down" machines.

Application Advertisement

Windows 2000 users can take advantage of application advertisement (also called "on-demand product installation"). On Windows 2000 platforms, the Windows installer advertises an application by placing the application's icon on the user's desktop and Start menu, without installing application files on the machine's hard disk drive. The application is available to the user but doesn't use installation processing, memory, or storage resources until the user specifically chooses to run the application. When this occurs, the Windows installer copies and installs the necessary files and components onto the target machine.

Windows 2000 administrators can use application advertisement to add application icons to the Start menu of many machines without installing any files on any machine until the machine's user selects the application icon. This gives system administrators the ability to maintain a single environment on multiple Windows 2000 machines that gives all users access to all applications, while only installing applications as applicable.

Installation on Locked Down Machines

Windows 2000 system administrators can give Windows installer packages permission to run with administrator privileges on user machines. This enables application installation on locked down Windows 2000 machines, where ordinary users don't have privileges to do the things the installation program may have to do.