To start a program:
(i) Click the Start button and then point to Programs. The Program menu appears.
(ii) Point to the group that contains the program you want to start, and then click the program name.
(iii) You can also open a program by clicking Run on the Start menu, typing the path and the name of the program, and then clicking OK.
(iv) To quit a program, click the Close button in the upper right comer of the program window.

A scrollbar is an interaction technique in which continuous text, pictures, or any other content can be scrolled in a predetermined direction (up, down, left, or right) on a computer display so that all contents can be viewed, even if only a fraction of the content can be seen on a device's screen at a time.

(i) The window is an area on the screen that displays information for a specific program.
(ii) Window is a typical rectangular area in an application or a document or a-dialog.
(iii) A typical window includes a title bar along the top that describes the contents of the window, A followed by a toolbar that contains user interface buttons.
(iv) Most of the window's remaining area is used to display the content.

(i) The opening screen of Windows is called "Desktop".
(ii) The desktop of your computer may look different
(iii) This is because Windows allows you to change the appearance of the desktop.
(iv) The desktop is the opening screen which consists of the icons as well as the Start button.
(v) The desktop can be used to store information temporarily or to move around documents and windows.

(i) An operating system (OS) is a software program that enables the computer hardware to communicate and operate with the computer software.
(ii) It also acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs.