Pass pre-requisite check information from Config file in InstallShield

I'm trying to achieve a requirement in Pr开发者_如何转开发e-requisites part of my package: The package should be able to check for the presence of a specific Operating System or Microsoft Patch on the target machine and block installation if the specified OS&patch is not found. I want to pass this information from Configuration xml or ini file, so that installer need not to be edited and build again for changes in requirements.

Any ideas on how to achieve this!!

Microsoft typically publishes the files affected by patches and their version number. You can use that to determine if the patch is applied.

As for the config file portion, I've never done this as if I make a change to an installer I generally want to rebuild it. I guess you could write a custom action to replace AppSearch/LaunchConditions and have it be data driven from an XML file instead of the built in tables but I'm still not sure I'd do it.