CompTIA A+ Certification

The Core consists of the Graphical Device Interface (GDI); the kernel; the user component; and the user interface. These four components have 32-bit and 16-bit dynamic-link libraries (DLLs) to allow the operating system to use the 32-bit mode while allowing backward 16-bit compatibility for old devices and applications.

• Graphical Device Interface (GDI) is an imaging system that draws all the objects displayed on the screen or reads the information to devices like printers that can receive graphical output. The GDI is also the component responsible for interacting with the display system and its related drivers. It is one of the most complex tasks performed by the operating system and many of the memory problems associated with earlier versions of Windows could be traced back to graphics display problems and GDI management.
• The User Interface is a 32-bit shell that includes a variety of tools to make use of the file system and gain access to system services. These include My Computer, the Network Neighborhood, and Windows Explorer. All Windows applications can make use of the shell services, including dialog boxes and the ability to list and view files.
• The User Component of the operating system functions as the I/O manager. It receives and routes input from the mouse, keyboard, microphone, and other input devices. It also routes traffic to and from the communications ports, the system timer, and the sound card. In addition, it functions as the output coordinator for the GDI by controlling the output of display elements like menus, dialog boxes, and icons.
• The Kernel controls all the tasks of the operating system. It invokes the executable file when an application opens, and terminates it when it is done; it loads and manages all DLLs and allocates memory; and is responsible for all pre-emptive multi-tasking and multi-threading operations.