Buy a retired corporate laptop with Windows XP and a physical COM port (Dell Latitude D630 or IBM ThinkPad T42). Install KPG-55D v4.01 and the 3.2.0.0 Prolific driver. That $50 laptop will program your TK-3107 for the next decade without a single error.
: Open your chosen software (e.g., KPG-55D) via your DOS emulator if necessary. Model Selection : Go to the "Model" menu and select Kenwood Tk 3107 Software Download Fix
: Ensure the communication port in the software settings matches the COM port assigned to your cable in the Windows Device Manager. If you get a "No COM port" error in DOS-based software, ensure the emulator is correctly mapped to your physical USB-to-Serial port. Cable Connection Buy a retired corporate laptop with Windows XP