 <p>You will need to set the flag called ecoReinstallInstalled (Installshield help does not mentioned this keyword) which is referred to in the document titled “Using Chained MSI Packages to Componentize Your Windows Installer Setup”.</p> <p>Basically, you change the ‘option’ column of the ISChainPackage table of the specified chained MSI by adding the value 16 to the current value. If the value is less than 16; for example, the value is 0, replace it with 16; if the value is 1, replace it with 17 and so on. The option value determines the UI Level mode (the mode in which the chained MSI will run); 0 for Basic UI, 1 for No UI, value 16 or above will allow the chained MSI to re-run after it has been already installed.</p> <p>If this does not work, which it should you need to check the chained MSI's log file by modifying the property IS_CHAINER_POST_COMMANDLINE, you could also try running the chained MSI in ui mode to see what the behaviour is.</p> <p>Interestingly what alternative did you use instead of the Chained MSI functionality?</p> <p>Look at my blog which by the way web page is work in progress:</p> <p><a href="http://installdeploy.com/wordpress/blog/" rel="nofollow">http://installdeploy.com/wordpress/blog/</a></p>