Process Lasso can quite easily be installed without any user interaction. To do so, simply add the /S switch to the command line installer. If you have an activation code, you can also specify it, along with all sorts of other data like the configuration file or path.
If doing unattended installs, it is required that you have the correct installer for your edition – Workstation or Server, 32-bit or 64-bit. Of the four, you need the right one. If you don’t, the installer will self-correct and lose these command line arguments in the process.