The file is the compiled version of the InstallScript ( Setup.rul ) file used by InstallShield to execute installation logic.
Because it is compiled object code, you cannot edit Setup.inx directly with a text editor. Developers must modify the original source script and recompile. Compiling Your Script Installshield Setup Inx
Installshield Setup INX is a setup file created by InstallShield, a software tool used to create installation packages for Windows applications. INX files are used to define the installation settings and options for an application. The file is the compiled version of the