This is typically a previous other installation stuck, or a problem in the Windows update/install processes.
If you see msiexec OR Paradox Launcher running in Task manager-processes, kill it and try this launcher install again please.
If still no good, do you see Paradox Launcher v2 in the Windows Control Panel to uninstall? If so does it uninstall cleanly, or get an error doing that? You can use this MS tool to clear the stuck install/uninstall:
If you see msiexec OR Paradox Launcher running in Task manager-processes, kill it and try this launcher install again please.
If still no good, do you see Paradox Launcher v2 in the Windows Control Panel to uninstall? If so does it uninstall cleanly, or get an error doing that? You can use this MS tool to clear the stuck install/uninstall: