System.ArgumentException: The given port name does not start with com/com or does not resolve to a valid serial port

Problem Description:

The program has been working normally, today the computer re-made the system, and then began to appear this problem: "The given port name does not start with com/com or resolves to a valid serial port." Serial debugging assistant is also not used. Serial cable is not a problem, it is not a hardware problem, the program is not a problem (normal operation on other computers).

Exception information:

{system.argumentexception: The given port name does not start with com/com or does not resolve to a valid serial port.
Parameter name: PortName
In System.IO.Ports.SerialStream. ctor (String portname, Int32 baudrate, Parity Parity, Int32 databits, StopBits stopbits, Int32 readtimeout, Int32 writetime Out, handshake handshake, Boolean dtrenable, Boolean rtsenable, Boolean discardnull, Byte parityreplace)
In System.IO.Ports.SerialPort.Open ()
In Oste_Scan500wpf.Serial.OpenPort () location d:\ My Documents \visual Studio 2010\projects\******* \serial.cs: line number 70}

Exception Reason:

It turned out that the Adobe PDF printer was using serial 1 (COM1), which prevented the program from opening serial 1.

Problem solving:

It would be nice to change the port of Adobe PDF to a different port.

System.ArgumentException: The given port name does not start with com/com or does not resolve to a valid serial port