Monday, February 24, 2014

how to format windows xp


Computers store their data and operating procedures on devices called Hard Disks. The process of removing all data from these disks is called (re)formatting. More often than most would like a computer's hard disk must be wiped clean, whether because a virus infection, or the disk may just be full.

Steps

1.
Back up your data. All important data should be backed up before starting this procedure.  Remember that all hard disk data will be lost when you reformat.. 

  


 2.
Insert the Windows XP CD-ROM or DVD-ROM into your computer.

 

3
Restart the PC.

 


4
Press any key. Soon after the power on self test (POST) a message similar to "Press any key to boot from CD" will appear. Press any key at this point. 



5
Press the F8 key to agree to the Microsoft end user license agreement when prompted to do so.

 


6
When the prompt showing available space is shown select each field that does not say "Unallocated Space".

  


7
Press d (for delete) followed by L (no need to capitalize) to confirm partition deletion.

  


8
Repeat steps 6 and 7 until the only field left is "Unallocated Space"

 


9
Press enter to install windows to the unallocated space, select Quick Format instead of standard. If you're reformatting to recover from error, you will want to do a Full Format otherwise your error may still exist. 

 


10
The PC should restart, then select your language and local preferences when prompted to do so.
  



11
When the administrator password prompt comes up enter the desired password.

 


12
All done, restore the documents you backed up before starting this procedure and re-install your applications.

 

Warnings

  • WARNING: To prevent severe electric shock and possible fire DO NOT insert the Windows disc if it is wet or dirty.
  • NOTE: When following this procedure, all user data will be erased, please back up data.
  • NOTE: Windows XP requires the following minimum PC requirements: 233 MHz processor.  128MB of system memory (RAM). 1.5 GBs of hard disk space. 800x600 minimum display resolution. A CD or DVD-ROM drive. A keyboard and mouse.

 

Video How To Format/Install  Windows XP On PC








 

desktop pc


File:Computer-aj aj ashton 01.svg
A desktop computer is a personal computer in a form intended for regular use at a single location, as opposed to a mobile laptop or portable computer. Early desktop computers were designed to lie flat on the desk, while modern towers stand upright. Most modern desktop computers have separate screens and keyboards.

Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small; the type of computers most commonly used were minicomputers, which were themselves desk-sized. Early personal computers, like the IBM PC, were enclosed in "desktop" cases, horizontally oriented to have the display screen placed on top, thus saving space on the user's actual desk. Over the course of the 1990s, desktop cases gradually became less common than the more-accessible tower cases that may be located on the floor under the desk rather than on a desk.



An all-in-one PC integrates the system's internal components into the same case as the display, allowing for easier portability and a smaller footprint, especially on designs using flat panel displays. Some recent all-in-one models also include touchscreen displays.

Apple has manufactured several popular examples of all-in-one computers, such as the original Macintosh of the mid-1980s and the iMac of the late 1990s and 2000s. This form factor was popular during the early 1980s for computers intended for professional use such as the Kaypro II, Osborne 1, TRS-80 Model II and Compaq Portable. Many manufacturers of home computers like Commodore and Atari included the computer's motherboard into the same enclosure as the keyboard; these systems were most often connected to a television set for display.

Like laptops, some all-in-one desktop computers are characterized by an inability to customize or upgrade internal components, as the systems' cases do not provide easy access except through panels which only expose connectors for RAM or storage device upgrades. However, newer models of all-in-one computers have changed their approach to this issue. Many of the current manufacturers are using standard off-the-shelf components and are designing upgrade convenience into their products.



 When referring to an operating system or GUI, the Desktop is a system of organization of icons on a screen. The Microsoft Windows Desktop was first introduced with Microsoft Windows 95 and has been included with all versions of Windows since then. Below is a basic example of the Microsoft Windows desktop.




In the above picture, is an example of the Microsoft Windows 95 Desktop. In this picture, there are Desktop icons on the left-hand-side of the window, blue and white clouds for the wallpaper, and the Taskbar is found on the bottom of the screen.

Tip: Press the shortcut key Windows key + D at any time to get to the Windows Desktop.

What icons and items are found on the Windows Desktop?












Some of the most common icons you're likely to find on the Desktop include the My Computer icon, Recycle Bin, your Internet browser icon (e.g. Internet Explorer), and My Documents. On the Windows Desktop, you'll also have access to the Windows Start Menu through the Start button on the Taskbar and the Windows Notification Area.




In some versions of Windows, you may be missing some or all of these icons, you can change what default icons show by following the steps in the below link.

pc program



A computer program, or just a program, is a sequence of instructions, written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor.The program has an executable form that the computer can use directly to execute the instructions. The same program in its human-readable source code form, from which executable programs are derived (e.g., compiled), enables a programmer to study and develop its algorithms. A collection of computer programs and related data is referred to as the software.

Computer source code is typically written by computer programmers. Source code is written in a programming language that usually follows one of two main paradigms: imperative or declarative programming. Source code may be converted into an executable file (sometimes called an executable program or a binary) by a compiler and later executed by a central processing unit. Alternatively, computer programs may be executed with the aid of an interpreter, or may be embedded directly into hardware.

Computer programs may be ranked along functional lines: system software and application software. Two or more computer programs may run simultaneously on one computer from the perspective of the user, this process being known as multitasking.

 



 

Programming



 Computer programming is the iterative process of writing or editing source code. Editing source code involves testing, analyzing, refining, and sometimes coordinating with other programmers on a jointly developed program. A person who practices this skill is referred to as a computer programmer, software developer, and sometimes coder.

The sometimes lengthy process of computer programming is usually referred to as software development. The term software engineering is becoming popular as the process is seen as an engineering discipline.


 

Paradigms


Computer programs can be categorized by the programming language paradigm used to produce them. Two of the main paradigms are imperative and declarative.

Programs written using an imperative language specify an algorithm using declarations, expressions, and statements.[4] A declaration couples a variable name to a datatype. For example: var x: integer; . An expression yields a value. For example: 2 + 2 yields 4. Finally, a statement might assign an expression to a variable or use the value of a variable to alter the program's control flow. For example: x := 2 + 2; if x = 4 then do_something(); One criticism of imperative languages is the side effect of an assignment statement on a class of variables called non-local variables.[5]

Programs written using a declarative language specify the properties that have to be met by the output. They do not specify details expressed in terms of the control flow of the executing machine but of the mathematical relations between the declared objects and their properties. Two broad categories of declarative languages are functional languages and logical languages. The principle behind functional languages (like Haskell) is to not allow side effects, which makes it easier to reason about programs like mathematical functions.[5] The principle behind logical languages (like Prolog) is to define the problem to be solved — the goal — and leave the detailed solution to the Prolog system itself.[6] The goal is defined by providing a list of subgoals. Then each subgoal is defined by further providing a list of its subgoals, etc. If a path of subgoals fails to find a solution, then that subgoal is backtracked and another path is systematically attempted.

The form in which a program is created may be textual or visual. In a visual language program, elements are graphically manipulated rather than textually specified.

 

Execution and storage

Typically, computer programs are stored in non-volatile memory until requested either directly or indirectly to be executed by the computer user. Upon such a request, the program is loaded into random access memory, by a computer program called an operating system, where it can be accessed directly by the central processor. The central processor then executes ("runs") the program, instruction by instruction, until termination. A program in execution is called a process. Termination is either by normal self-termination or by error — software or hardware error.

Automatic program generation


Generative programming is a style of computer programming that creates source code through generic classes, prototypes, templates, aspects, and code generators to improve programmer productivity. Source code is generated with programming tools such as a template processor or an integrated development environment. The simplest form of source code generator is a macro processor, such as the C preprocessor, which replaces patterns in source code according to relatively simple rules.

Software engines output source code or markup code that simultaneously become the input to another computer process. Application servers are software engines that deliver applications to client computers. For example, a Wiki is an application server that lets users build dynamic content assembled from articles. Wikis generate HTML, CSS, Java, and JavaScript which are then interpreted by a web browser.

 

Functional categories


Computer programs may be categorized along functional lines. The main functional categories are system software and application software. System software includes the operating system which couples computer hardware with application software.The purpose of the operating system is to provide an environment in which application software executes in a convenient and efficient manner. In addition to the operating system, system software includes utility programs that help manage and tune the computer. If a computer program is not system software then it is application software. Application software includes middleware, which couples the system software with the user interface. Application software also includes utility programs that help users solve application problems, like the need for sorting.

Sometimes development environments for software development are seen as a functional category on its own, especially in the context of human-computer interaction and programming language design.[clarification needed] Development environments gather system software (such as compilers and system's batch processing scripting languages) and application software (such as IDEs) for the specific purpose of helping programmers create new programs. 


















input devices


In computing, an input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or other information appliance. Examples of input devices include keyboards, mouse, scanners, digital cameras and joysticks.


Many input devices can be classified according to:
 modality of input (e.g. mechanical motion, audio, visual, etc.)

the input is discrete (e.g. key presses) or continuous (e.g. a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous)the number of degrees of freedom involved (e.g. two-dimensional traditional mice, or three-dimensional navigators designed for CAD applications)
Pointing devices, which are input devices used to specify a position in space, can further be classified according to:

Whether the input is direct or indirect. With direct input, the input space coincides with the display space, i.e. pointing is done in the space where visual feedback or the pointer appears. Touchscreens and light pens involve direct input. Examples involving indirect input include the mouse and trackball.
    Whether the positional information is absolute (e.g. on a touch screen) or relative (e.g. with a mouse that can be lifted and repositioned)

Direct input is almost necessarily absolute, but indirect input may be either absolute or relative.[clarification needed] For example, digitizing graphics tablets that do not have an embedded screen involve indirect input and sense absolute positions and are often run in an absolute input mode, but they may also be set up to simulate a relative input mode like that of a touchpad, where the stylus or puck can be lifted and repositioned.
Input and output devices make up the hardware interface between a computer and a scanner or 6DOF controller.

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Following are few of the important input devices, which are used in Computer Systems:
  •     Keyboard
  •     Mouse
  •     Joystick
  •     Light pen
  •     Track Ball
  •     Scanner
  •     Graphic Tablet
  •     Microphone
  •     Magnetic Ink Card Reader (MICR)
  •     Optical Character Reader (OCR)
  •     Bar Code Reader
  •     Optical Mark Reader


 

Keyboard

Most common and very popular input device is keyboard. The keyboard helps in inputting the data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing some additional functions.
Keyboards are of two sizes 84 keys or 101/102 keys, but now 104 keys or 108 keys keyboard is also available for Windows and Internet.
The keys are following:

Sr. No.
Keys
Description
1
Typing Keys
These keys include the letter keys (A-Z) and digits keys (0-9) which generally give same layout as that of typewriters.
2
Numeric Keypad
It is used to enter numeric data or cursor movement. Generally, it consists of a set of 17 keys that are laid out in the same configuration used by most adding machine and calculators.
3
Function Keys
The twelve functions keys are present on the keyboard. These are arranged in a row along the top of the keyboard. Each function key has unique meaning and is used for some specific purpose.
4
Control keys
These keys provide cursor and screen control. It includes four directional arrow key. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc).
5
Special Purpose Keys
Keyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen.
Keyboard



 

Mouse

Mouse is most popular Pointing device. It is a very famous cursor-control device. It is a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU on pressing the buttons.
Generally, it has two buttons called left and right button and scroll bar is present at the mid. Mouse can be used to control the position of cursor on screen, but it cannot be used to enter text into the computer.

Advantages

  • Easy to use
  • Not very expensive
  • Moves the cursor faster than the arrow keys of keyboard.
Mouse


 

Joystick

Joystick is also a pointing device, which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions.
The function of joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games.
Joy Stick


 

Light Pen

Light pen is a pointing device, which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a small tube.
When light pen's tip is moved over the monitor screen and pen button is pressed, its photocell sensing element, detects the screen location and sends the corresponding signal to the CPU.
Light Pen

 

 

Track Ball

Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball, which is half inserted and by moving fingers on ball, pointer can be moved.
Since the whole device is not moved, a track ball requires less space than a mouse. A track ball comes in various shapes like a ball, a button and a square.
Track Ball

 

Scanner

Scanner is an input device, which works more like a photocopy machine. It is used when some information is available on a paper and it is to be transferred to the hard disc of the computer for further manipulation.
Scanner captures images from the source which are then converted into the digital form that can be stored on the disc. These images can be edited before they are printed.
Scanner

 

Digitizer

Digitizer is an input device, which converts analog information into a digital form. Digitizer can convert a signal from the television camera into a series of numbers that could be stored in a computer. They can be used by the computer to create a picture of whatever the camera had been pointed at.
Digitizer is also known as Tablet or Graphics Tablet because it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for doing fine works of drawing and images manipulation applications.
Graphic Tablet

 

Microphone

Microphone is an input device to input sound that is then stored in digital form. The microphone is used for various applications like adding sound to a multimedia presentation or for mixing music.
Microphone

 

Magnetic Ink Card Reader (MICR)

MICR input device is generally used in banks because of a large number of cheques to be processed everyday. The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable.
This reading process is called Magnetic Ink Character Recognition (MICR). The main advantage of MICR is that it is fast and less error prone.
Magnetic Ink Card Reader(MICR)

 

Optical Character Reader (OCR)

OCR is an input device used to read a printed text. OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.
Optical Character Reader(OCR)

 

Bar Code Readers

Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labelling goods, numbering the books, etc. It may be a hand-held scanner or may be embedded in a stationary scanner.
Bar Code Reader scans a bar code image, converts it into an alphanumeric value, which is then fed to the computer to which bar code reader is connected.
Bar Code Readers

 

Optical Mark Reader (OMR)

OMR is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked. It is specially used for checking the answer sheets of examinations having multiple choice questions.
Optical Mark Reader(OMR)






operating system



An operating system (OS) is a collection of software that manages computer hardware resources and provides common services for computer programs. The operating system is an essential component of the system software in a computer system. Application programs usually require an operating system to function.

Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the  application code is usually executed directly by the hardware and will frequently make a system call to an OS function or be interrupted by it. Operating systems can be found on almost any device that contains a computer—from cellular phones and video game consoles to supercomputers and web servers.

Examples of popular modern operating systems include Android, BSD, iOS, Linux, OS X, QNX, Microsoft Windows, Windows Phone, and IBM z/OS. All these, except Windows, Windows Phone and z/OS, share roots in UNIX.

An operating system is a program that acts as an interface between the software and the computer hardware.
It is an integration set of specialised programs that are used to manage overall resources and operations of the computer.
It is a specialised software that controls and monitors the execution of all other programs that reside in the computer, including application programs and other system software.




Types of operating systems

Real-time
  •     A real-time operating system is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main objective of real-time operating systems is their quick and predictable response to events. They have an event-driven or time-sharing design and often aspects of both. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.


Multi-user
  •     A multi-user operating system allows multiple users to access a computer system at the same time. Time-sharing systems and Internet servers can be classified as multi-user systems as they enable multiple-user access to a computer through the sharing of time. Single-user operating systems have only one user but may allow multiple programs to run at the same time.


Multi-tasking vs. single-tasking
  •     A multi-tasking operating system allows more than one program to be running at the same time, from the point of view of human time scales. A single-tasking system has only one running program. Multi-tasking can be of two types: pre-emptive and co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking, as does AmigaOS. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking. 32-bit versions of both Windows NT and Win9x, used pre-emptive multi-tasking. Mac OS prior to OS X used to support cooperative multitasking.


Distributed
  •     A distributed operating system manages a group of independent computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system.


Embedded
  •     Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems.  



Objectives of Operating System

  •  Making a computer system convenient to use in an efficient manner.
  • To hide the details of the hardware resources from the users.
  • To provide users a convenient interface to use the computer system. 

  • To act as an intermediary between the hardware and its users and making it easier for the users to access and use other resources.
  • Manage the resources of a computer system.
  • Keep track of who is using which resource, granting resource requests, according for resource using and mediating conflicting requests from different programs and users.
  • The efficient and fair sharing of resources among users and programs.
Operating System 

Characteristics of Operating System



  • Memory Management -- It keeps track of primary memory, i.e., what parts of it are in use by whom, what parts are not in use, etc. Allocates the memory when the process or program requests it.
  • Processor Management -- Allocates the processor (CPU) to a process. Deallocate processor when processor is no longer required.
  • Device Management -- Keeps tracks of all devices. This is also called I/O controller. Decides which process gets the device when and for how much time.
  • File Management -- Allocates the resources. Deallocates the resource. Decides who gets the resources.
  • Security -- By means of passwords & similar other techniques, preventing unauthorized access to programs & data.
  • Job accounting -- Keeping track of time & resources used by various jobs and/or users.
  • Control over system performance -- Recording delays between requests for a service & from the system.
  • Interaction with the operators -- The interaction may take place via the console of the computer in the form of instructions. Operating System acknowledges the same, do the corresponding action and inform the operation by a display screen.
  • Error-detecting aids -- Production of dumps, traces, error messages and other debugging and error-detecting methods.
  • Coordination between other software and users -- Coordination and assignment of compilers, interpreters, assemblers and other software to the various users of the computer systems.

mac os



Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The original version was the integral and unnamed system software first introduced in 1984 with the original Macintosh, and referred to simply as the "System" software. The System was renamed to Mac OS in 1996 with version 7.6. The System is credited with popularizing the graphical user interface concept.

Mac OS releases have existed in two major series. Up to major revision 9, from 1984 to 2000, it is historically known as Classic Mac OS. Major revision 10 (revisioned minorly, such as 10.0 through 10.9), from 2001 to present, has had the brand name of Mac OS X and now OS X. Both series share a general interface design and some shared application frameworks for compatibility, but also have deeply different architectures.


Design concept


 Apple's original inception of the System deliberately sought to minimize the user's conceptual awareness of the operating system. Tasks which required more operating system knowledge on other systems would be accomplished by intuitive mouse gestures and simple graphic controls on a Macintosh, making the system more user-friendly and easily mastered.  This would differentiate it from then current systems, such as MS-DOS, which were more technically challenging to operate.

The core of the system software was held in ROM, with updates originally provided free of charge by Apple dealers (on floppy disk). The user's involvement in an upgrade of the operating system was also minimized to running an installer, or simply replacing system files. This simplicity is what differentiated the product from others.
 



OS X


OS X, introduced as Mac OS X and renamed OS X in 2012, is the latest version of Apple's operating system. Although it is officially designated as simply "version 10" of the Mac OS, it has a history largely independent of the earlier Mac OS releases.

The operating system is the successor to Mac OS 9 and the "classic" Mac OS. It is however a Unix-like operating system, based on the NeXTSTEP operating system and the Mach kernel which Apple acquired after purchasing NeXT Computer - with its CEO Steve Jobs returning to Apple at that time. OS X also makes use of the BSD code. There have been ten significant releases of OS X, the most recent being OS X 10.9, referred to as Mavericks. Prior to 10.9 came 10.8 - Mountain Lion, 10.7 - Lion, 10.6 - Snow Leopard, 10.5 - Leopard, 10.4 - Tiger, 10.3 - Panther, 10.2 - Jaguar, 10.1 - Puma, 10.0 - Cheetah.

OS X also had six significant releases as OS X Server. The first of these, Mac OS X Server 1.0, was released in beta in 1999. The server versions are architecturally identical to the client versions, with the differentiation found in their inclusion of tools for server management, including tools for managing OS X-based workgroups, mail servers, and web servers, amongst other tools. As of the name change to OS X, OS X Server is no longer sold as a separate operating system product. The server tools could then be added to the singular OS X product, giving the same functionality.

OS X Server is available as an operating system to-order on Mac Mini and Mac Pro computers as a part of a server package. Unlike the client version, OS X Server can be run in a virtual machine using emulation software such as Parallels Desktop and VMware Fusion.

OS X is also the basis for iOS, (previously iPhone OS) used on Apple's iPhone, iPod Touch, iPad, and Apple TV.