This book is Volume 6 of the series, FYSOS: Operating System Design, and will show the reader how to create a Graphical User Interface, with all the bells and whistles that go along with it. It will show how to draw to the video screen, create windows and objects such as, buttons, menus, bitmaps, progress bars, and other objects. It will show how to send event messages so that other windows can communicate with the root object, suchas when a button is pressed, a text edit is changed, or any other change in the GUI system. All of this is done with minimal outside help, such as operating system calls, though a few calls to the BIOS are needed to retrieve the video hardware information. The reader will learn how to communicate with the video directly, reading and writing pixels to the screen to achieve these tasks. The companion CD-ROM contains complete source code of each example within the book, showing how to accomplish these tasks, and is heavily commented. The source code is a must to be able to follow along with the book, and is freely available once proof of book purchase is provided. This book, and its companion series of books, does not expect you to build the next great wonder of the computer world. It simply will help you with your interest in controlling the computer’s hardware, from the point the BIOS releases execution to your boot code to the point of a fully working Graphical User Interface. It is not required that you know much about operating system design, though a good knowledge of C Programming Language and a moderate knowledge of an Intel®/AMD® x86 computer’s hardware is expected to use this book.