we haven't tested the behaviour of /S flag. Can you please try installing the drivers alone using dpinst-amd64.exe /lm /sw /sa /q
Sorry for reviving this old thread. I stumbled upon it and thought I'd share how I do it.1. Install manually on some computer. When the trust dialog appears check "always trust".2. Start the Windows certificates manager (Start -> Run... -> certlm.msc). Find the Arduino certificate under "Trusted Publishers". Export it.3. Add the commandcertutil -addstore TrustedPublisher "<full path to exported certificate file>"to your deployment before running the installer. It should now be able to silently install the drivers.