I remember times I have used InnoSetup for creating the installations of the software applications. In those times there were also other tools like Nullsoft and similar. From the “big ass” installers those days I remember only few – InstallAware and InstallShield (where last one was the most powerful and heavy one).
But some time ago I saw a new tool developed which has an integration with the Delphi IDE. And the tool I am talking about now is RAD & Installer. What it does is integrating the NSIS (Nullsoft installer) and InnoSetup into Delphi IDE! So that you can make the installers directly from the development environment.
I think you can give it a try if you ever used mentioned systems.