Windows 7 sometimes assigns a high COM port number (like COM12 or COM24) that older sign software cannot read.
While the machine has a physical USB port, the internal electronics do not communicate via native USB. Instead, the plotter utilizes a built-in . When you plug the USB cable into your Windows 7 PC, the computer looks for a virtual COM port driver rather than a "printer" driver. Goldcut Jk-series Driver Windows 7
All these models utilize a based on either: Windows 7 sometimes assigns a high COM port