Patching

InstallShield 2024

Project: This information applies to the following project types:

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Basic MSI

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InstallScript MSI

Patching is a streamlined mechanism for updating earlier versions of a Windows Installer installation package, thereby updating the application. With a patch, you deliver to your customers only the bits required to change an installed file into a new file. One benefit of a patch is that the size of the upgrade package can be significantly smaller than the full-installation package required to deliver the same upgrade. Keeping an upgrade package as small as possible allows you to more easily deliver your upgrades over the Internet.

However, you should note that a patch may not always present the best solution. For example, if you want to change your installation from compressed to uncompressed, or vice versa, you should package your upgrade as a full installation, but not as a patch. To learn more about determining the best packaging option for your upgrade, see Packaging Options for Upgrades.

A patch is delivered in the form of a patch package (.msp) file, which your end user can apply to an installed product. A patch package is capable of updating as many earlier versions of an installation package as required. A patch package contains separate transforms and instructions for updating each previous version that you specify.

An important aspect of patch creation is generating a patch creation properties (.pcp) file, which defines the parameters on which the patch package is to be created. The .pcp file is a database that has a specific schema, but you can open it and edit it directly with InstallShield or Orca.

The Patch Design view provides an easy-to-use interface to simplify the patch creation process. This view groups together all the logical considerations you will need to make in patch creation.