Most developers understand the benefits of writing reusable code. It makes sense to use that piece again when you need the same functionality. The more pre-tested software you can reuse, the fewer bugs you’re likely to have in the final product.
Merge modules extend the notion of reusable components to the software installation process. Once you’ve developed a way to install a reusable component, you can also reuse the installation process!
This article explains the Merge Modules, the need of it and How to merge them to an existing installer file (.msi).
Upgrades are little complex compared to the new installer. This guest article from Bhuvana aims at providing the requirement for minor upgrade, the steps to create it and options to install the same. Minor upgrade is a type of Product upgrade that Windows Installer supports. A minor upgrade can be used to add new features and components. Let us know if you have any inputs / suggestions for Minor upgrade.