In order to access the Serial Port using Visual Basic, we need to add a component to the standard components in the control toolbox

This can be done by executing a right-click on the control toolbox.

Select the components to add new components to the control toolbox

Check the check-box named "Microsoft Comm Control"

This Comm Control is the OCX responsible for controlling the PC serial ports

MSCOMM32.OCX will be called everytime an access to the serial port will be executed by the program

You can now see in the control toolbox an additional Icon which represents a picture of a telephone and modem.

This Icon should be present in the control toolbox in order to be able to create applications controlling the PC Serial ports.

Add the control to the form that you are using. This icon is visible only on editing while hidden during runtime.

The default name of the control is MSCOMM1. You may change the name as you wished using the properties panel.