Posted 08 March 2002 - 12:44
I can't tell you how to make one MSI directly dependant on another, but you can search for already installed files, registrykeys, components, etc.
You may make your MSI use the AppSearch action to look for needed prerequisits and stop your installation with a Type 19 custom action which displays a specified error message, returns failure, and then terminates the installation. This Type 19 CA must be conditioned with a property evaluated during AppSearch and could show your user a message telling him what's missing.
For further info on searching for apps etc look for "Searching for Existing Applications, Files, Registry Entries or .ini File Entries" in the Windows installer documentation.