You may either select a port from the list provided, or you may enter a port name directly.

The port list provided is edited to remove ports that are already present in your system. You can override this by creating another (eg) COM1, but this is not recommended, and may lead to system instability.

Serial ports do not have to begin COM, they can have any name. However, many applications that operate with serial ports only provide for a subset of fixed names, sometimes as limited as COM1 through COM4. Under these circumstances, you have to configure a port in the Redirector that matches a port that is both available, and can be selected from your target application.