rkcl notes in english

Windows Basic

What is Operating System

An operating system is the program that manages all the other programs in a computer after being initially loaded into the computer by a boot program. It is the most basic program in a computer.

The other programs are called applications or application programs. The application programs make use of the operating system by making requests for services through a defined application program interface (API).

The functions of an operating system can be classified into three groups:

1) Managing resources

2) Providing user interface

3) Running applications

The operating system’s job is to control the computer at the most fundamental level. It manages memory, controls access to peripheral devices and serves as a translator between the user and the hardware, providing the means for the user and application programs to tell the hardware what to do.

Users interact with application programs and computer hardware through a “user interface”. Many older operating systems use a character-based interface in which users communicate with the operating system through written commands. Almost all newer operating systems use a “graphical user interface (GUI)”.

Operating systems load and run applications such as word processors and spreadsheets. Most operating systems support “multitasking” which is the ability to switch between different applications stored in memory.

Starting or restarting a computer is called “booting” the system. There are two ways to boot a computer, a warm boot and a cold boot. A “warm boot” occurs when the computer is already on and you restart it without turning off the power. For example, in Windows Vista, you can restart a running computer by pressing the “Start” button, clicking on the arrow at the bottom right and selecting “Restart”. Starting a computer that has been turned off is called a “cold boot”.

Users can interact directly with the operating system through a user interface such as a command language or a graphical user interface (GUI). Most GUIs provide a place called the “desktop”, which allows access to computer resources. Examples of operating systems are: Windows, Novell Netware, Mac OS, UNIX and Linux.

Operating systems have several features in common with application programs, such as the following ones.

Icons: These are graphic representations for a program or function.

Pointer: This is controlled by a mouse and changes shape depending on its current function. For example, when shaped like an arrow, the pointer can be use to select items such as an icon.

Windows: These are rectangular areas for displaying information and running programs.

Menus: These provide a list of options or commands.

Dialog Boxes: These are window that provide information or request input.

Help: Online assistance is provided for different operations and procedures.

Most operating systems store data and programs in a system of files and folders. Unlike the traditional filing cabinet, computer files and folders are stored on a secondary storage device such as your hard disk.”Files” are used to store data and programs. Related files are stored within a “folder”. A folder may also contain other folders.

There are various operating systems, but they all can be categorized under three basic heads: embedded, network and stand-alone.

“Embedded operating systems” are used for handheld computers and smaller devices like PDAs. The operating system programs are stored on read-only memory (ROM) chips and embedded in the device. Popular embedded operating systems include Windows CE and Windows XP Embedded.

“Network operating systems” are used to control and coordinate computers that are linked together. Network operating systems are generally located on one of the hard disks of the connected computers. This computer is called the “network server” and it coordinates communication between the other computers. Popular network operating systems include Netware, Windows NT Server, Windows XP Server and UNIX.

“Stand-alone operating systems” also called “desktop operating systems”, control a single desktop or notebook computer. These operating systems are located on the computer’s hard disk. Popular desktop operating systems include Windows, Mac OS and some versions of UNIX.

Often desktop computers and notebooks are part of a network. In such cases, the desktop operating system works with the network’s NOS to share and coordinate resources. Here, the desktop operating system is referred to as the “client operating system”.

The operating system is often referred to as the “software environment” or “platform”. Almost all application programs are designed to run with a specific platform. For example, the standard version of AppleWorks is designed to run with the Mac OS environment.

Microsoft Windows

Microsoft Windows is a range of closed source commercial operating environments for personal computers and servers. The range was first introduced by Microsoft in 1985 and eventually has come to dominate the world personal computer market.

Microsoft’s Windows is the most popular microcomputer operating system with over 90 percent of the market. Because of this, a large number of application programs are developed to run under Windows. Windows comes in a variety of versions and is designed to run with Intel and Intel-compatible microprocessors such as the Pentium IV.

You can see details of the various Microsoft desktop operating systems in the displayed figure.

The most widely used versions of Windows, i.e. Windows XP, was introduced in 2001. The next major version, Windows Vista, which is the latest one, was released in 2007.

Some of the useful features of Windows are as follows:

You can see multiple programs running simultaneously on different areas of your screen.

The Windows interface is based on “Graphical User Interface” or GUI, which means that the interface uses graphics or pictures to help the user navigate and access programs. Right-clicking the mouse on any object displays a “context” menu which you can use to execute many useful commands easily.

You can use shortcuts to open a program without having to find the program on your hard disk.

Help is always near. Pressing the “F1” key in most situations either displays detailed instructions or brief descriptions of the controls. The help has a search feature, too, allowing you to find desired information by typing in a keyword.

Clipboard: The “Clipboard” is a temporary storage area for information that you have copied or moved from one place and plan to use somewhere else. For example, you might want to copy a section of text from a website, and then paste that text into an e mail message. The Clipboard is available in most Windows programs.

Other Operating System

“Mac OS” is the trademarked name for a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface. It is a powerful, easy-to-use operating system that is popular with professional graphic designers, desktop publishers and many home users.

One of the latest versions of the Macintosh operating system is “Mac OS X”, also known as “Tiger”. It provides powerful features such as “Spotlight” and “Dashboard Widgets”. Spotlight is an advanced search tool that can rapidly locate files, folders, e-mail messages, addresses and much more. Dashboard Widgets are specialized programs that constantly update and display information.

The next version of Mac OS, “Leopard” includes “Boot Camp” which allows appropriately equipped Apple computers to use both Mac OS and Windows XP.

UNIX and Linux: UNIX is a powerful multitasking operating system that was developed in 1969. It was originally designed to run on minicomputers in network environments. Now, it is also used by powerful microcomputers and Web servers.

Linux is a popular version of UNIX. It was initially created as a hobby in 1991 by a graduate student, Linus Torvalds, at the University of Helsinki in Finland. He allowed free distribution of the operating system code and encouraged others to modify and further develop the code.