Authors of installation packages should include upgrading information in their .msi files to ensure that their installation package can take advantage of the full upgrading functionality available with the Microsoft Windows Installer.

Every application, or suite of applications, should be assigned an UpgradeCode Property, ProductVersion Property, and ProductLanguage Property. The UpgradeCode property indicates a family of related applications consisting of different versions and different language versions of the same product. For more information about using the UpgradeCode property, see Using an UpgradeCode.

Preparing an application for future major upgrades

1. Determine a new package code value for the application. For more information about package codes, see Package Codes. Enter the new package code into the Revision Number Summary Property of the Summary Information Stream.
2. Determine a new ProductCode property for the application. See Changing the Product Code for more information. Enter ProductCode and its value into the Property table.
3. Determine the application's version and the ProductVersion property. The ProductVersion should increase with each new version of the application. Note that the installer uses only the first three fields of the product version. If you include a fourth field in your product version, the installer ignores the fourth field. Enter ProductVersion and its value into the Property table.
4. Determine the language of the package and the ProductLanguage property. The value of this property must be a numeric language identifier (LANGID). Enter ProductLanguage and its value into the Property table. Note that the FindRelatedProducts action uses the language returned by MsiGetProductInfo. For FindRelatedProducts to work correctly, the package author must be sure that the ProductLanguage property is set in the Property table to a language that is also listed in the Template Summary property.
5. If you are authoring an installation package for the first version of your product, use a new UpgradeCode. If your package is intended for a newer version of an existing product, or is the same version as an existing product in a different language, use the same UpgradeCode as the existing product. No two products with the same ProductVersion and the same ProductLanguage can have the same UpgradeCode, unless one is a small update of the other.
6. The UpgradeCode has the format of a GUID. Enter the UpgradeCode GUID into the Property table.

For more information, see Preventing an Old Package from Installing Over a Newer Version.

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Build date: 8/13/2009