Inno Setup Unpacker is an open-source command-line tool which can extract the contents of Inno Setup installers.

This could enable you to run applications without having to install them first, although there are no guarantees. The installer is supposed to prepare your system for its application to ensure it works correctly, so if you try to bypass this step then it may no longer run.

Inno Setup Unpacker is a console application, but straightforward enough to use. Forget the command line switches to list file contents, test for integrity, define paths and so on - most people can get by with nothing more than this:

innounp -x setup.exe

This tells Inno Setup Unpacker to extract the components of setup.exe into the current folder.

If your executable isn't an Inno Setup installer, you'll get an error. If it is, you'll probably see an install_script.iss file - the script which holds the instructions for the installer - and an [app] folder with the application's various components.

Check the [app] folder to see what it contains. If it's very simple, maybe a readme file, an internet shortcut and an executable, you can probably run it immediately without installation.

The more complicated it gets, maybe with drivers to install and services to set up, the more difficult it's going to be to run it without installing. But if you must, for some reason, checking the install_script.iss will show you what the installer tries to do. And then you just have to do much the same thing yourself.

Version 0.46:
    - Increased max. LZMA dictionary size to 1Gb (implemented in IS 5.5.9).