The Repackaging Process

Windows Installer provides no functionality for repackaging applications. However, numerous vendors sell repackaging products for Windows Installer. See the next section, "Repackaging Tools," for a list of vendors.

Repackaging is not new. Organizations have historically repackaged applications to customize their installation and configuration. However, Windows Installer transforms eliminate the need to repackage Windows Installer-based applications just to customize them. In fact, repackaging applications that already install from a Windows Installer setup database is bad practice and is not supported.

Repackaging an application is a process that compares snapshots to determine the contents of the new package. The following steps provide an overview of the repackaging process:

1. Take a snapshot of the computer's current configuration.
2. Install the application.
3. Take a second snapshot of the computer's new configuration.
4. Create a package that contains the differences between the two snapshots. The repackaging tool detects all of the differences between the two snapshots, including all changes to the registry and file system. Because numerous processes are running in Windows 7 at any time, the package file will likely contain settings and files related to processes outside of the application.
5. Clean the package to remove noise (unnecessary files and settings).

Warning Don't let the simplicity of these five steps trick you into believing that repackaging is easy. Application repackaging is very often the most expensive part of any deployment project. When you undertake the repackaging of an organization's applications, you can count on a labor- and resource-intensive effort, particularly in organizations with thousands of applications, many of which the organization must repackage. Budget, plan, and schedule accordingly.

Repackaging Tools

You must use tools that are not included with Windows Installer to create Windows Installer packages. The following list includes some of the variety of tools available:

• AdminStudio Available in multiple versions, including a free download, AdminStudio is a powerful and flexible repackaging tool. The following versions are available:
  • AdminStudio Configuration Manager Edition This free download from Microsoft integrates with System Center Configuration Manager 2007 to simplify repackaging. AdminStudio Configuration Manager Edition prepares legacy Setup.exe packages for deployment by converting them to Windows Installer .msi packages. To download AdminStudio Configuration Manager Edition, see http://technet.microsoft.com/en-us/configmgr/bb932316.aspx.
  • AdminStudio Professional Edition This full version of AdminStudio is a complete solution for packaging, customizing, testing, and distributing applications. The full version includes all the features included with AdminStudio Configuration Manager Edition, plus additional features. To download a trial version of AdminStudio, see the AdminStudio software overview page at http://www.acresso.com/products/as/adminstudio-overview.htm.
• Wise Package Studio Wise offers products for repackaging, testing, and configuring the deployment of applications. See http://www.symantec.com/business/package-studio for more information.