Particularly if you work in an environment where you are limited to assigning applications to computers using group policy as a means of deployment- bypassing the need to run MSI files with their accompanying setup.exe file is important. Using the property ISSETUPDRIVEN=1 from the command line or in a transform bypasses the bootstrapping process the setup.exe provides to ensure the appropriate version of InstallShield script is present on your system. These methods (and the use of AdminStudio's InstallScript Scan feature) are discussed and demonstrated in the video "Dealing with InstallScript for Administrators". However you do it, make sure this does not end up breaking you deployment by deploying some or all of the InstallShield Script versions available. You may download each from the links below:

InstallShield Script v11

InstallShield Script v10

InstallShield Script v9

InstallShield Script v8

InstallShield Script v7

InstallShield Script v2 and below