I have a few component msi packages that need to installed together to form the end application. The problem is: the components that make up the package can be updated and the component relaunched on the http file server.What approach should i take? The installer that i am writing is the 'master' installer. Which needs to be able to read what version of each component is installed on ther client machine in order to perform an upgrade only on that one component. Also if the application is installed for the first time the installer will download and install all required components. I am using Installshield 2009. I have looked into chained MSI's but the master installer is empty. as it needs to be as lightweight as possible. I have no idea how to write a bootstrapper application and my company perfers that i use installshield to write the installer. I have researched - and apparently pre-requisites are not meant to be uninstalled.