Comprehensive Computer Learning: All about Operating Systems, Windows, Photoshop, Microsoft Office, DTP, Tally, Printing, and Emails

By Joygopal Poddar

The book is designed to provide you with everything you need for your formal introduction to the world of computers. It's the one book that covers everything that a reader needs to know about computers - Hardware and software of a computer; setting up a new computer; using Microsoft Office and other popular software connecting to the Internet; working with digital media; burning custom CD/DVD; watching movies; managing money online; setting up home networks; keeping PCs running reliably; protecting your PC from spam, viruses, and spyware; cleaning your PC properly, etc. This comprehensive guide uses easy-to-follow steps and screenshots, and clear, concise language to show the simplest ways to get things done with your PC. #v&spublishers

• Language: English
• Publisher: V&S Publishers
• Release date: Jan 29, 2013
• ISBN: 9789350574089

Book preview

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Chapter 1

An Introduction

What is a Computer?

Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic Computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

Types of Computers

Computers range in size and capability. At one end of the scale are supercomputers, very large computers with thousands of linked microprocessors that perform extremely complex calculations. At the other end are tiny computers embedded in cars, TVs, stereo systems, calculators, and appliances. These computers are built to perform a limited number of tasks.

The personal computer, or PC, is designed to be used by one person at a time. This section describes the various kinds of personal computers: desktops, laptops, handheld computers, and Tablet PCs.

Desktop Computers

Desktop Computers are designed for use at a desk or table. They are typically larger and more powerful than other types of personal computers. Desktop computers are made up of separate components. The main component, called the system unit, is usually a rectangular case that sits on or underneath a desk. Other components, such as the monitor, mouse, and keyboard, connect to the system unit.

Desktop Computer

Laptop Computers

Laptop computers are lightweight mobile PCs with a thin screen. They are often called notebook computers because of their small size. Laptops can operate on batteries, so you can take them anywhere. Unlike desktops, laptops combine the CPU, screen, and the keyboard in a single case. The screen folds down onto the keyboard when not in use.

Laptop computer

Handheld computers

Handheld Computers, also called personal digital assistants (PDAs), are battery-powered computers small enough to carry almost anywhere. Although not as powerful as desktops or laptops, handhelds are useful for scheduling appointments, storing addresses and phone numbers, and playing games. Some have more advanced capabilities, such as making telephone calls or accessing the Internet. Instead of keyboards, handhelds have touch screens that you use with your finger or a stylus (a pen-shaped pointing tool).

Handheld Computer

Tablet PCs

Tablet PCs are mobile PCs that combine features of laptops and handhelds. Like laptops, they're powerful and have a built-in screen. Like handhelds, they allow you to write notes or draw pictures on the screen, usually with a tablet pen instead of a stylus. They can also convert your handwriting into typed text. Some Tablet PCs are convertibles with a screen that swivels and unfolds to reveal a keyboard underneath.

What can you do with computers?

In the workplace, many people use computers to keep records, analyze data, do research, and manage projects. At home, you can use computers to find information, store pictures and music, track finances, play games, and communicate with others—and those are just a few of the possibilities.

You can also use your Computer to connect to the Internet, a network that links Computers around the world. Internet access is available for a monthly fee in most urban areas, and increasingly, in less populated areas. With Internet access, you can communicate with people all over the world and find vast information.

Here are some of the most popular things to do with computers:

The web

The World Wide Web (usually called the Web, or web) is a gigantic storehouse of information. The web is the most popular part of the Internet, partly because it displays most information in a visually appealing format. Headlines, text, and pictures can be combined on a single webpage—much like a page in a magazine—along with sounds and animation. A website is a collection of interconnected webpages. The web contains millions of websites and billions of webpages.

A Webpage (Microsoft Game Studios)

Surfing the web means exploring it. You can find information on the web about almost any topic imaginable. For example, you can read news stories and movie reviews, check airline schedules, see street maps, get the weather forecast for your city, or research a health condition. Most companies, government agencies, museums, and libraries have websites with information about their products, services, or collections. Reference sources, such as dictionaries and encyclopedias, are also widely available.

The web is also a shopper's delight. You can browse and purchase products—books, music, toys, clothing, electronics, and much more—at the websites of major retailers. You can also buy and sell used items through websites that use auction-style bidding.

Email

Email (short for electronic mail) is a convenient way to communicate with others. When you send an email message, it arrives almost instantly in the recipient's email inbox. You can send email to many people simultaneously, and you can save, print, and forward email to others. You can send almost any type of file in an email message, including documents, pictures, and music files. And with email, you don't need a stamp!

Instant messaging

Instant messaging is like having a real-time conversation with another person or a group of people. When you type and send an instant message, the message is immediately visible to all participants. Unlike email, all participants have to be online (connected to the Internet) and in front of their computers at the same time. Communicating by means of instant messaging is called chatting.

Pictures, music, and movies

If you have a digital camera, you can move your pictures from the camera to your computer. Then you can print them, create slide shows, or share them with others by email or by posting them on a website. To learn more about what you can do with photos, You can also listen to music on your computer, either by importing (transferring to your computer) music from audio CDs or by purchasing songs from a music website. Or, tune in to one of the thousands of radio stations that broadcast over the Internet. If your computer comes with a DVD player, you can watch movies.

Gaming

Do you like to play games? Thousands of computer games in every conceivable category are available to entertain you. Get behind the wheel of a race car, battle frightening creatures in a dungeon, or control civilizations and empires! Many games allow you to compete with other players around the world through the Internet.

History of Computers

A Computer history timeline is described as follows:

Counting aids -Manual caculators Mechanical calculators Programmable calculators Programmable computers

The Table below explains the History of Computers in detail:

Photographs of some computers described below:

We shall now look at working of a computer

Working of a computer

First question that might strike your mind is how do computer works, here is a brief explanation:

Powering on the computer

When you first press the power button the computer sends a signal to the computer power supply, which converts the alternating current (AC) into a direct current (DC) to supply the computer and its components with the proper amount of voltage and electricity.

Once the computer and its components have received ample power and the power supply reports no errors it sends a signal (using transistors) to the motherboard and the computer processor (CPU). While this is happening, the processor will clear any leftover data in the memory registers and give the CPU program counter a F000 hexadecimal number. This number is the location of the first instruction and tells the CPU that it's ready to process the instructions contained in the basic input/output system (BIOS).

BIOS and the POST

When the computer first looks at the BIOS, it begins the power-on self-test (POST) sequence to make sure the components in the computer are present and functioning properly. If the computer does not pass any of these tests, it will encounter an irregular POST. An irregular POST is a beep code that is different from the standard one or two beeps. For example, an irregular POST could generate no beeps at all or a combination of different beeps to indicate the cause of the failure.

If the computer passes the initial POST, it will next look at the first 64-bytes of memory located in the complementary metal oxide semiconductor (CMOS) chip, which is kept alive by the CMOS battery even when the computer is turned off. This chip contains information such as the system time and date and information about all the hardware installed in your computer.

After loading the CMOS information, the POST will begin inspecting and comparing the system settings with what is installed in the computer. If no errors are found it will then load the basic device drivers and interrupt handlers for hardware such as the hard drive, keyboard, mouse, floppy drive. These basic drivers allow the CPU to communicate with these hardware devices and allow the computer to continue its boot process.

Next, the POST will check the real-time clock (RTC) or system timer and the computer system bus to make sure both of these are properly working on the computer. Finally, you'll get a picture on your display after the POST has loaded the memory contained on the display adapter and has made it part of the overall system BIOS.

Next, the BIOS will check to see if it's currently performing a cold boot or warm boot (reboot) by looking at the memory address 0000:0472, if it sees 1234h the BIOS knows that this is a reboot and will skip the remainder of the POST steps.

If 1234h is not seen, the BIOS knows that this is a cold boot and will continue running additional POST steps. Next, it tests the computer memory (RAM) installed in the computer by writing to each chip. With many computers, you'll know it's performing this step if you see the computer counting the total installed memory as it's booting.

Finally, the POST will send signals to the computer floppy, optical, and hard drive to test these drives. If all drives pass the test, the POST is complete and instruct the computer to start the process of loading the operating system.

Booting the operating system

After the computer has passed the POST, the computer will start the boot process. This process is what loads the operating system and all of its associated files. Because Microsoft Windows is the most commonly used operating system, this section will cover the process of loading Microsoft Windows.

The BIOS first hands control over to the bootstrap loader, which looks at the boot sector of the hard drive. If your boot sequence in CMOS setup is not setup to look at the hard drive first, it may look at the boot sector on any inserted floppy disk drive or optical disc first before doing this.

In this example, the Microsoft Windows XP NT Loader (NTLDR) is found on the boot sector and tells the computer where to find the remaining code on the hard drive. Next, Windows loads the ntdetect.com file, which displays the Windows splash screen and loads the Windows registry. After loading the registry, Windows begins to load dozens of low- level programs that make up the operating system into memory. Many of the initially loaded programs are what allow Windows to communicate with the essential hardware and other programs running on the computer.

After the registry has loaded the initial basic hardware devices, it begins to load Plug and Play devices, PCI, and ISA devices. After loading all these devices, Windows then moves to loading full support of the hard drive, partitions, and any other disk drives and then moves to all other drivers that have been installed.

Finally, after successfully completing the above steps any additional required services are loaded and Windows starts.

Hardware devices communicating with the computer

After the computer has loaded the operating system, hardware attached to the computer must be able to communicate with the CPU. Hardware communication is done by using an interrupt request (IRQ). Each time a hardware device needs the attention of the computer the interrupt controller sends the request (INTR) to the CPU so it temporarily stops what it is doing to process the request of the hardware device. Anything that was being currently done by the CPU is put on hold and stored as a memory address in the memory stack and is returned to after the interrupt request is processed.

Hardware and Software

Computers work through an interaction of hardware and software. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. The most important piece of hardware is a tiny rectangular chip inside your computer called the central processing unit (CPU), or microprocessor. It's the brain of your computer—the part that translates instructions and performs calculations. Hardware items such as your monitor, keyboard, mouse, printer, and other items are often called hardware devices, or devices.

Software refers to the instructions, or programs, that teil the hardware what to do. A word processing program that you can use to write letters on your computer is a type of software. The operating system (OS) is Software that manages your computer and the devices connected to it. Two well-known operating systems are Windows and Macintosh operating system. Your computer uses the Windows operating system.

Parts of a Desktop Computer

Here is the description of an average desktop computer.

Parts of a computer

If you use a desktop computer, you might already know that there isn't any single part called the computer. A computer is really a system of many parts working together. The physical parts, which you can see and touch, are collectively called hardware. (Software, on the other hand, refers to the instructions, or programs, that teil the hardware what to do.)

The illustration below shows the most common hardware in a desktop computer system. Your system may look a little different, but it probably has most of these parts. A laptop computer has similar parts but combines them into a single notebook-sized package.

Focusing on Key PC Components

Let's explore different components of PC

System unit

The system unit is the core of a Computer system. Usually it's a rectangular box placed on or underneath your desk. Inside this box are many electronic components that process information. The most important of these components is the central processing unit (CPU),

System unit

or microprocessor, which acts as the brain of your computer Another component is random access memory (RAM), which temporarily stores information that the CPU uses while the computer is on. The information stored in RAM is erased when the computer is turned off.

Almost every other part of your computer connects to the system unit using cables. The cables plug into specific ports (openings), typically on the back of the system unit. Hardware that is not part of the system unit is sometimes called a peripheral device or device.

Central Processing Unit (CPU)

The central processing unit (CPU, occasionally central processor unit is the hardware within a computer system which carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system. CPU consists of RAM(Random Access Memory), Processors & BIOS Chips.

Microprocessor SSOP

Monitor

A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures.

There are two basic types of monitors: CRT (cathode ray tube) monitors and LCD (liquid crystal display) monitors. Both types produce sharp images, but LCD monitors have the advantage of being much thinner and lighter. CRT monitors, however, are generally more affordable.

LCD monitor (left); CRT monitor (right)

IO Devices - Keyboard/Mouse

A keyboard is used mainly for typing text into your computer. Like the keyboard on a typewriter, it has keys for letters and numbers, but it also has special keys:

Keyboard

The function keys, found on the top row, perform different functions depending on where they are used.

The numeric keypad, located on the right side of most keyboards, allows you to enter

numbers quickly.

The navigation keys, such as the arrow keys, allow you to move your position within a

document or webpage.

You can also use your keyboard to perform many of the same tasks you can perform with a mouse.

A mouse is a small device used to point to and select items on your computer screen. Although mice come in many shapes, the typical mouse does look a bit like an actual mouse. It's small, oblong, and connected to the system unit by a long wire that resembles a tail. Some newer mice are wireless.

Mouse

A mouse usually has two buttons: a primary button (usually the left button) and a secondary button. Many mice also have a wheel between the two buttons, which allows you to scroll smoothly through screens of information.

When you move the mouse with your hand, a pointer on your screen moves in the same direction. (The pointer's appearance might change depending on where it's positioned on your screen.) When you want to select an item, you point to the item and then click (press and release) the primary button. Pointing and clicking with your mouse is the main way to interact with your computer.

Scanner

scanner—is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning Hand-held scanners, where the device is moved by hand, have evolved from text scanning wands to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.

Printer

A printer transfers data from a computer onto paper. You don't need a printer to use your computer, but having one allows you to print email, cards, invitations, announcements, and other materials. Many people also like being able to print their own photos at home. The two main types of printers are - inkjet printers and laser printers. Inkjet printers are the most populär printers for the home.

Laser printer

They can print in black and white or in full colour and can produce high-quality photographs when used with special paper. Laser printers are faster and generally better able to handle heavy

use.

Inkjet printer

Webcam

A webcam is a video camera that feeds its images in real time to computer or computer network, often via USB, ethernet, or Wi-Fi.

Their most popular use is the establishment of video links, permitting Computers to act as videophones or videoconference stations. The common use as a video camera for the World Wide Web gave the webcam its name. Other popular uses include security surveillance, computer vision, video broadcasting, and for recording social videos.

Hard Drive

Your computer has one or more disk drives—devices that store information on a metal or plastic disk. The disk preserves the information even when your computer is turned off.

Hard disk drive

Hard disk drive

Your computers hard disk drive stores Information on a hard disk, a rigid platter or stack of platters with a magnetic surface. Because hard disks can hold massive amounts of information, they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit.

Optical Drive for CDs and DVDs

Nearly all computers today come equipped with a CD or DVD drive, usually located on the front of the system unit. CD drives use lasers to read (retrieve) data from a CD, and many CD drives can also write (record) data onto CDs. If you have a recordable disk drive, you can store copies of your files on blank CDs. You can also use a CD drive to play music CDs on your computer.

DVD drives can do everything that CD drives can, plus read DVDs. If you have a DVD drive, you can watch movies on your computer. Many DVD drives can record data onto blank DVDs.

Floppy disk drive

Floppy disk drives store information on floppy disks, also called floppies or diskettes. Compared to CDs and DVDs, floppy disks can store only a small amount of data. They also retrieve information more slowly and are more prone to damage. For these reasons, floppy disk drives are less popular than they used to be, although some computers still include them.

Floppy disk

Video Adapter

A video Adapter (also called a display card, graphics card, graphics board, display adapter or graphics adapter) is an expansion card which generates a feed of output images to a display. Most video cards offer various functions such as accelerated rendering of 3D scenes and 2D graphics, MPEG-2/MPEG-4 decoding, TV output, or the ability to connect multiple monitors (multi-monitor).

Sound Card

A sound card (also known as an audio card) is an internal Computer expansion card that facilitates the input and output of audio signals to and from a Computer under control of Computer programs. The term sound card is also applied to external audio interfaces that use Software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection.

Sound functionality can also be integrated onto the motherboard, using basically the same components as a plug-in card. The best plug-in cards, which use better and more expensive components, can achieve higher quality than integrated sound. The integrated sound system is often still referred to as a sound card.

Ports and Jacks

In computer hardware, a port serves as an interface between the computer and other computers or peripheral devices. Physically, a port is a specialized outlet on a piece of equipment to which a plug or cable connects. Electronically, the several conductors making up the outlet provide a signal transfer between devices.

Modem

To connect your computer to the Internet, you need a modem. A modem is a device that sends and receives computer information over a telephone line or high-speed cable. Modems are sometimes built into the system unit, but higher- speed modems are usually separate components.

Bluetooth Wireess Adapter

Desktop devices using Bluetooth technology are available. With a base Station that connects via cables to the fixed-line telephone and also the computer via soundcard, users with any Bluetooth headset can pair their headset to the base station, enabling them to use the same headset for both fixed-line telephone and Computer VoIP communication. This type of device, when used together with a multiple-point Bluetooth headset, enables a single Bluetooth headset to communicate with a computer and both mobile and landline telephones.

Bluetooth Adapter

Touchpad

A touchpad (or trackpad) is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. Touchpads are a common feature of laptop computers, and are also used as a substitute for a mouse where desk space is scarce. Because they vary in size, they can also be found on personal digital assistants (PDAs) and some portable media players. Wireless touchpads are also available as detached accessories.

Touchpad

Speakers, Mics & Headphones

Speakers are used to play sound. They may be built into the system unit or connected with cables. Speakers allow you to listen to music and hear sound effects from your computer. While Mics are used to record/ send voice.

Computer speakers

A microphone (colloquially called a mic or mike is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors.

Chapter 2

The First Steps

Buying the Right Computer for You

When buying a PC, you have much more to consider than simply whether you want a desktop PC, notebook, or netbook. You need to think not only about portability, but also processor type and speed, disk storage capacity, memory, CD/DVD drives, audio, video, operating system, and a whole lot more. In addition, you want to find the right PC at the best price.

Well, you've come to the right place. This chapter explains key considerations, provides guidance on making the right choices for your needs, and shows you how to shop for great deals on PCs.

Assessing Your Computing Needs

Your choice of PC hinges on the reasons you're getting a new PC and how you plan to use it. Check all items that apply.

Focusing on Mobility

If you need or want to travel with your PC, mobility is the first and most important consideration. You can rule out entire categories of computers based solely on how portable you need your PC to be. The following sections describe your options from least to most mobile/portable.

Desktop PC

Desktop PCs are the largest, sturdiest, heaviest, and least portable of the bunch, but they offer three major advantages:

More bang for your buck: A comparably equipped portable PC costs several thousands more.

More suitable for meeting advanced needs: A top-of-the-line desktop model can do things a top-of-the-line portable PC may not, such as play the latest video games at warp speed and produce theater-quality video and sound.

More room to grow: Desktop models typically offer more Upgrade options to meet future needs.

Desktop models also come as space-saving all-in-one PCs that look like a monitor with a mouse and keyboard attached (with cables or without). All-in-one models often have touchscreens to make them even easier to use.

Notebook (Laptop)

Notebook PCs, also called laptops, include everything most users need in a single, compact unit that typically weighs less than lkilogram.

Tablet PC

A tablet PC is like a notebook with a screen that pivots, folds back, and allows you to write on it. It's perfect for people who need to jot down handwritten notes, sign digital documents, or pivot the screen to show something to clients. Real estate agents, financial planners, investment brokers, and others who must travel, present information to clients, and have them sign documents often find a tablet PC the ideal solution.

Netbook

Netbooks are streamlined notebooks designed primarily to use the Internet and perform basic tasks. They typically have smaller screens and keyboards, weigh about % kg or less, and are very affordable. The biggest drawback may be the lack of an internal CD or DVD drive. You can add an external CD or DVD drive, but it just isn't quite the same.

Recommendation

I always recommend notebooks, tablet PCs, or larger netbooks over desktop models. Why? Because you can connect a mouse and a full-size keyboard and monitor to a portable computer to make it more like a desktop model, but you can't make a desktop model any smaller or lighter. Some portable PCs even have optional docking stations to enable you to quickly and easily connect the PC to any and all external devices.

Buying Key Components

A PC is a collection of components designed to work as a unit. When you start shopping, you'll encounter lists of components along with specifications for each component. The following sections describe the most important components and what to look for based on your needs.

Central Processing Unit (CPU)

The central processing unit (CPU) or processor is the computer's brain; it performs all the calculations for the computer. When choosing a CPU, consider the following factors:

Architecture: This is the overall design of the CPU. One of the most important design considerations is the number of cores the CPU has. Multi-core processors, including dual- and quad-core processors, are like having two, three, or four processors built into a single CPU.

Clock speed: Measured in gigahertz (GHz), clock speed indicates how fast the CPU processes instructions.

L2 cache: Also known simply as cache, L2 cache is temporary storage built into the chip for recently or frequently used data and instructions. It helps the CPU function at top speed.

Front side bus: This is the path that connects the CPU to other key components, including memory. Front side bus speed is measured in gigabytes—the faster, the better.

Operating System

You can tell a lot about a computer by checking the version of Windows 7 that's installed on it. First, check whether the PC has a 32- or 64-bit version of Windows 7. The 32-bit version is fine for most needs and may be best if you have older 32-bit hardware or software you want to use. If you're looking for a performance boost or starting from scratch, lean toward a PC that runs the 64-bit version of Windows. The 64-bit PCs and software handle larger amounts of memory (4GB and higher). All computers that have the Windows 7 Compatible logo can run either the 32- or 64-bit version.

After choosing between the 32- and 64-bit version, you have another choice to make:

Windows Starter, Home Premium, Professional, or Ultimate edition.

Windows Starter: This is a streamlined version exclusively for netbooks.

Home Premium: Windows 7 Home Premium can handle all your basic needs, simplify the process of setting up a home network, and manage all your media and entertainment needs, including managing and sharing photos, videos, and music; watching, recording, and copying DVDs; listening to, recording, and copying CDs; and watching and recording TV shows (with the addition of a TV tuner).

Professional: Windows Professional has everything Home Premium has, plus a few features typical for businesses: Running Windows XP productivity programs in Windows XP Mode, automatically backing up files to your home or business network, and connecting easily and securely to your company network from remote locations.

Ultimate: Windows Ultimate has everything included in the Professional edition, plus the ability to encrypt data on a portable PC or portable storage device, features for IT professionals, and support for 35 different languages.

Windows Vista: Earlier Version of Windows available in many Variants as of Windows 7

Windows XP: Earlier Version of Windows comes without Driver Support, Still used in Many systems with Low Grade Configuration.

Random Access Memory (RAM)

Random access memory (RAM), often referred to simply as memory, stores all the data and instructions the PC requires to perform its job while it's on. When you turn off your PC, everything is erased from memory. When shopping for RAM, consider the following:

Amount: I recommend at least 2GB for most users and 4GB for serious media, entertainment, and gaming junkies. If the PC comes with the 32-bit version of Windows, don't bother with more than 4GB.

Type and speed: Look for DDR2 or DDR3 SDRAM and compare speeds, measured in gigabytes. DDR stands for double data rate, and SDRAM stands for synchronous dynamic random access memory. Just remember that DDR2 is good, DDR3 is better, and higher speed translates into better performance and higher cost.

Upgradeability: Make sure you can add more RAM later to meet your future needs. See Shopping for a PC with Room to Grow later in this chapter for details.

Hard Drive

The computer's hard drive is a disk inside the computer that stores data permanently; when you turn the computer off, the data remains on the disk. When comparing hard drives in different PCs, consider the following factors:

Storage capacity: Size or storage capacity is measured in gigabytes. 250GB is usually more than enough. Photographers, videographers, serious gamers, and game designers require more space—at least 500GB.

Speed: Speed is measured in revolutions per minute (RPMs) and is directly related to the rate at which the drive can read data from the disk. A speed of 5400 RPMs is standard and sufficient for most needs. High-end users should consider speeds of at least 7200 RPMs.

Interface: The Serial ATA (SATA) interface is standard and sufficient for most needs. A SATA drive coupled with motherboard that supports it can transfer data at up to 300MB per second. Steer clear of the older ATA (also called IDE) interface. SCSI is another high-performance option.

Buffer: A buffer is memory built into the drive to store data temporarily so the system doesn't need to wait for the relatively slow-spinning disk to read frequently accessed data and instructions. Most hard drives have an 8MB buffer, which is sufficient for most needs; 16MB or more is better.

Optical Drive for CDs and DVDs

Optical drive is another name for CD or DVD drive. When comparing optical drives, consider the following features:

Multi-format: Most optical drives are multi-format, meaning you can use them to store computer data and play or record CDs or DVDs. Opt for a multi-format DVD+RW—a single drive that can handle all of these tasks.

Speed: Speed is expressed as X (times), which describes how fast the drive can write data to the disc. 8X is standard, but I recommend 16X or faster. Recording with an 8X drive is pretty slow, even if you don't burn discs all that often.

Interface: You have the same choices here as you do with hard drives: ATA (IDE) or SATA. Again, I recommend going with a SATA interface, but in the case of optical drives, ATA (IDE) is sufficient and very common.

Slot or tray load: With a slot-load drive, you insert the disc like a quarter in a pop machine, which is cool, easy, and efficient. Traditional drives require you to eject a tray, place a disc on it, and then load the tray.

Dual-layer support: Some optical drives can read from and write to both sides of a dual-layer disc, essentially doubling its storage capacity. If you plan to back up files, dual-layer DVD+RW are great; otherwise, this feature isn't all that important.

Laser disc labelling: Many optical drives (often referred to as LightScribe burners) can print labels on discs designed to have labels printed on them, which is pretty cool but not all that important.

Blu-ray support: Planning to watch high-definition movies on your computer? Then consider a Blu-ray drive. In addition to being able to play Blu-ray video, these drives can store up to 50GB on a single disc. If you're planning to copy a lot of CDs or DVDs, having two drives makes the job much easier.

Video Adapter

A video adapter processes the data required to display images on a monitor. Many computers include integrated video (part of the motherboard) supporting one or more of the following standards:

Digital Visual Interface (DVI): DVI enables you to play high-definition video.

High-Definition Media Interface (HDMI): Like DVI, HDMI is designed for high-definition video. The only difference is that HDMI carries both video and sound, whereas DVI carries only video. Computers typically support one or the other.

Blu-ray support: Blu-ray discs are copy-protected by AACS technology, so if you're planning to watch high-definition video, make sure the PC supports High-Bandwidth Digital Content Protection (HDCP) decoding. Most important is that the PC you buy have the right port (DVI or HDMI) for the monitor you choose. You may encounter some older PCs and monitors that support the VGA standard, but this is obsolete. Top-line PCs have a separate video card (or two). If you're a hardcore video game player, look for a PC that has a separate video card.

Video Standard: PCIe (Peripheral Component Interconnect Express) is a big step up in speed and performance from the older Accelerated Graphics Port (AGP) standard.

Memory: Graphics cards have their own memory to improve display quality and performance. 256MB is standard; 1GB is better for serious game players, photographers, or videographers.

Dual display support: Look for a PC that allows you to connect two monitors so you have the option of a dual-display configuration. This allows you to expand your desktop, so that you can, for example, have your e-mail displayed in one window while you're working on a document in the other.

Multiple display support: Hardcore game players often opt for systems with multiple video cards (as many as four) linked together for optimum display quality and performance. If this is what you have in mind, look for systems that support the nVidia Scalable Link Interface (SLI) or ATI Crossfire technology.

DirectX 10: Newer graphics cards support DirectX 10 (DX10), Microsoft's multimedia technology for displaying realistic images with complex lighting and shading effects.

DVI or HDMI support with HDPC decoding: DVI or HDMI is essential for playing Blu-ray DVDs and taking advantage of advanced graphics and animation in video games.

Monitor

A monitor displays everything so you can see what you're doing. Make sure the monitor you're getting is large enough for your needs and clear enough for your eyes. The following list describes the most important characteristics to consider:

Size: Size is the most important consideration. Don't settle for anything smaller than 15 inches, unless you're shopping for a netbook