I succeed in launching more than one instance of CVI by calling each of them via Start menu icon, next loading the proper project by File>Open menu item. As far as I can see, when more than one CVI instances are opened, double clicking on a prj in Windows Explorer opens it in the last CVI instance loaded. CVI remembers the project that was loaded in the instance that was closed LAST and represents it the next time it is restarted (unless a specific project is loaded at start or the -newproject command-line option is used...)