On some client workstations (Win 10) installed in PDM Pro Viewer 2019 SP2, the PDM client is launched systematically and automatically by Windows when the user is logged in (the PDM icon is visible in the taskbar).
What triggers this automatic launch when the user has not yet navigated the PDM view in Windows Explorer.
You go to the "Task Manager" on the "Startup" tab and there you should see "SOLIDWORKS PDM" in the "Activated" status. Or if you go through "Ccleaner" in the "Tools" menu tab "Startup" you must have the "Conisio Login manager" program activated when Windows starts.