The PDF24 Creator setup is created with InnoSetup. Therefore you can use all the command flags which are documented on InnoSetup developer page. There is also flags for installing in silent mode without user interaction.
If you have downloaded the pdf24.exe you can start the setup with
pdf24.exe /SILENT or with
pdf24.exe /VERYSILENT
When installing with argument /SILENT, the setup installs the pdf24 creator without user interaction but display the installation process.
When installing with argument /VERYSILENT, the setup installs pdf24 creator without user interaction to, but don't displays the installation process.
This is very nice for firms which wants to install the pdf24 creator on client pc's via network.