Summary

In order to find bugs that are occurring only with certain hardware or software configurations, you may need to debug your installation on a system other than your development machine. In that case, it is not necessary to install InstallShield on that computer.

Resolution

1. On testing machine, install C++ 2012 redistributable x86
2. Create folder on desktop to have a place to store files
3. Copy ISDbg.exe and SciLexer.dll (ISdbg.chm is optional) from the InstallShield\System folder to the new folder on the test machine
   1. (Be sure to use the same version of the files that the project used, ie a 2021 project will use the files from the 2021 version of InstallShield)
4. Using an administrative command prompt, register ISDbg.exe using the command below:

   ISDbg.exe /REGSERVER

5. Copy the entire project folder from the development machine to the new folder on the test machine
6. On the command prompt, change directories to the setup.exe and run the command below:

   setup.exe /d"<Path to Setup.dbg>"

   (setup.dbg will be found in the "scripts" subfolder of your project)

7. Walk through your installer until the debugger is triggered.

For Basic MSI

Debugging Basic MSI project with InstallScript CustomAction

setup.exe /v"ISSCRIPTDEBUG=1 ISSCRIPTDEBUGPATH=\"C:\Debugger\My Project Name-14\Script Files\""

NOTE: From Installshield 2023 onwards to run the IS2023 debugger ISdbg.exe in different machine, we need to install VC2022redist.exe (Please install attached VC2022redist package then try debugging)

Reference

Debugging Installscript help 

Setup.exe commandline Parameters