Silent Installations using Inno Setup

Inno Setup is a free installer for Windows software. It is not as popular as Windows Installer (MSI), but still widely used.

Applications distributed using Inno Setup can usually be installed silently, unless there are custom actions that didn’t take into consideration the scenario of a silent install.

The most used parameters of an Inno Setup are:

/SILENT – Runs the setup silently. The wizard and the background window are not displayed. However, the installation progress will be shown. In case of a necessary reboot, if the /NOREBOOT parameter is NOT mentioned, there will be a prompt asking for reboot.
/VERYSILENT – Same as /SILENT, but it doesn’t show the progress. If the /NOREBOOT switch is not used and a reboot is needed, the setup will automatically restart the machine.
/LOG=”filename” – logs the installation to a file. Quotes are important.
/NORESTART – suppresses the reboot messages and instructs setup not to restart when the installation is done, even if it’s needed.
/SAVEINF=”filename” – saves the installation configuration to the specified file. Quotes are important.
/LOADINF=”filename” – loads a previously saved installation configuration.

Other switches:
/SUPPRESSMSGBOXES – only when combined with the /SILENT and /VERYSILENT switches, it suppresses most of the dialog boxes. When there’s a choice, it uses the default option (No for overwriting files, Abort when there’s an Abort/Retry option, Yes when asked about keeping a newer file, Yes for restart).
/SP- – disables the “This will install…” prompt at the beginning.
/CLOSEAPPLICATIONS – Closes applications that hold files needing to be updated.
/NOCLOSEAPPLICATIONS – Prevents the setup from closing applications that hold files needing to be updated.
/RESTARTAPPLICATIONS – Applications closed by the setup will restart.
/NORESTARTAPPLICATIONS – Closed applications will not restart.
/DIR=”path” – Sets the installation directory. It overrides whatever the user has mentioned in the Select Destination Path wizard page. Full path.
/GROUP=”folder name” – Provides the name of the shortcut folder.
/NOICONS – No shortcuts created.
/TYPE=typeName – Overrides the default setup type (Complete, Custom, Minimal)
/COMPONENTS=”component1,component2,etc” – selects a list of components to be installed
/TASKS=”task1,task2,etc” – selects a number of tasks (such as desktopicon, fileassoc)
/MERGETASKS=”task3,task4″ – adds additional tasks to the default ones.
Both task params can also negate (!) a task: !desktopicon
/PASSWORD=password – specifies a password to use

For Uninstall, the unins000.exe (or higher index) from the installation directory must be called, with one of the following parameters: