Overview of ISSetup.dll

InstallShield 2018

ISSetup.dll is a C++ MSI DLL that contains the full InstallScript scripting run-time engine. For InstallScript MSI, Basic MSI, DIM, and Merge Module projects, ISSetup.dll executes InstallScript custom actions. For InstallScript projects, ISSetup.dll must be in the Disk1 folder.

Your installation always uses the InstallScript scripting run-time engine with which it was built, even if more a more recent version is installed on a target machine by another installation.

Important • Note the following information:

ISSetup.dll allows you to add only 1,000 InstallScript custom actions to your InstallScript MSI, Basic MSI, DIM, or Merge Module project. If your project includes more than 1,000 InstallScript custom actions, a build error is generated.
The version of ISSetup.dll that is used for InstallScript projects is different than the one that is used in InstallScript MSI, Basic MSI, DIM, and Merge Module projects. These two versions are not interchangeable.

See Also