I have just moved my SolidWorks 2009 to my Windows 10 computer and am trying to use the API with Visual Studio 2008. I am having mixed results with API functions such as boolstatus = swModel.Extension.SelectByID2("Top Plane", "PLANE", Cx, Cy, Cz, True, 0, Nothing, 0) and swModel.SetUserPreferenceDoubleValue(32, 0.002 / 39.37) or swApp = CreateObject("SldWorks.Application") I am getting the "Parameter is not valid." most of the time, not always. Any suggestions would be appreciated. Does anyone know whether or not the Solid Works 2009 XP 64 will work correctly with Windows 10?