in the past few weeks, I can no longer use Cura 15.04.06..(will not open COM port 3, as it always has in the past). I have not made any changes, but I did install another printing program .IT however uses the same port configuration (COM 3), that Cura does. I have uninstalled the other software program, uninstalled the driver for COM 3, and re-installed the driver, but I cannot open the port. VSRY frustrating..to say the least, can anyone help? It will use CURA 3.4.........WINDOWS 10/64.............