CertiGuide to A+ (A+ 4 Real)  9  Chapter 1: What are Operating Systems and How Do They Work?       9  Operating System Features            9  CDI versus GUI Interface

Command-Driven Interface 1 Graphical User Interface

Figure 3 shows the Windows Command Prompt interface. This is often mistakenly called a “DOS Prompt” due to its similarity to the interface provided by MS DOS. The distinction here is important. Under Windows NT, 2000 and XP, this interface is actually provided by an application called “cmd.exe” that emulates the functions of MS DOS. The subtle difference is that Windows NT, 2000 and XP do not run on top of MS DOS and therefore have a command prompt emulator. Windows 95, 98 and ME do run on top of DOS, and use “command.com” to provide an interface to the underlying MS DOS operating system.

To use this interface, users are required to type the exact format of the command as expected by the operating system, which can often include many options (known as “switches”). This interface is powerful but arcane, and is quite unforgiving if the commands and syntax used are incorrect. It is therefore a prerequisite that some time is allocated to studying the interface and its commands prior to actually using it. The major benefit of a CDI is the speed and power with which you can achieve results, allowing you to be more productive than if you limited yourself to just the GUI. It is also important to note that many core operating system commands are only accessible from the CDI; therefore, knowledge of its proper use is essential.

To access the command prompt, click the Start button and select the Run option. Under Windows 95 and 98, type “command.com” and press return. For Windows 2000, XP and Windows 2003, type “cmd.exe” in the run box and press return.

Command-Driven Interface 1 Graphical User Interface