INNO Setup is a free installer for Windows programs available at JRSoftware. There is no official unpacker – the only method of getting the files out of the self-extracting executable is to run it. An open source utility called innounp.exe is maintained at Sourceforge. Sourceforge has maintained version 0.19 online for over a year, however, 0.20 also exists from Sourceforge, if you know the link. With the introduction of INNO Setup version 5.2.3, the existing versions of innounp have proven to be unsuccessful. I recently discovered that another version of innounp.exe exists and is maintained by ..:: LeecherMods ::.. .

This is a list of files available with the version 0.23 download. innounp.exe is in Chinese, however, does work in the English environment just fine.

I was unable to get this innounp.exe to work with Universal Extractor 1.6, however, did work with InnounW.exe a GUI written in English.

In this example, I decompressed UltraISO 9. Below is a folder structure of the contents.

This is the contents of the .iss file.

Innounp, the INNO Setup Unpacker Downloads
Version 0.19 (2007.02.23) supports INNO 3.0.0-beta through 5.1.10
Version 0.20 (2008.05.23) supports INNO through 5.2.2
Version 0.23 (2008.03.18) supports INNO through 5.2.3 (Chinese)
Version 0.23 (2009.09.25) supports INNO through 5.2.3
Version 0.46 (2016.04.11) supports INNO 2.0.7 through 5.5.9
Version 0.49 (2019.05.09) supports INNO 2.0.7 through 6.0.2
Version 0.50 (2020.12.18) supports INNO 2.0.7 through 6.1.2