There are two InnoSetup scripts:

InstallerFull.iss:
 - Used for making complete installers.
 - Data files are taken from the folder BuildFull.


InstallerUpdate.iss:
 - Used for making complete installers.
 - Data files are taken from the folder BuildFull.


There are instructions at the top of each file explaining what you need to change before compiling. (e.g. revision number)


List of steps:

 1. Place all files to be installed in the build folder (update or complete)
 2. Open up the InstallerFull.iss or InstallerUpdate.iss script with InnoSetup
 3. Update the items described at the top of that file (revision, updatable versions)
 4. Compile!