This is the fourth in a series of articles concerning Windows SDK development that I have written over the years. The first three are: 1.Win32 SDK Data Grid View Made Easy [^] 2.Win32 SDK C Tab Control Made Easy [^] 3.Win32 SDK C Autocomplete Combobox Made Easy [^] Several years ago, I wanted to have a simple to use, message based, serial port control that I could employ in my Win32 C projects. I started experimenting with the idea and playing around with the serial port in my spare time, but as so often happens, the project ended up on the shelf when I got busy again. Recently, I came across that project and, with a better understanding of how serial port communications work on Windows, decided to finish it. Since I haven't encountered a serial port wrapper that takes this approach anywhere, I decided to publish it on The Code Project.