Computer BasicsWhat is a ComputerWhether you realize it or not, computers play important roles in our lives. When you get cash from an ATM, get your groceries scanned at the store or use a calculator, you're using a computer. A computeris a machine that manipulates information or "data." You can use a computer to type documents, send email, and surf the Internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and desktop publishing. A Brief History of ComputersThe first electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946. It measured 18 feet by 80 feet and weighed 30 tons. Today's desktop computers weigh much less, can store a million times more information, and are 50,000 times faster.The first personal computersor PCswere introduced in the 1970s. PCs came into widespread use in the 1980s as costs decreased and machines became more powerful.In recent years, notebook-size laptop computersand hand-held Personal Digital Assistants (PDAs)have become popular. You'll learn more about these devices in Lesson 5.Parts of the ComputerA computer is made up of several different parts.The system unit is the metal and plastic box that contains the main components of the computer. Computer cases come in different shapes and sizes. A desktop caselies flat on a desk, and the monitor usually sits on top of it. A tower case, pictured right, is tall and sits next to the monitor or on the floor. Parts of the Computer•The front of the case usually has an on/off switchandtwo or more drives. (You'll learn more about the CD ROM drive in later modules.)•On the back of the computer case are connection portsmade to fit only one type of plug-in device. The ports include monitor cable port, keyboard/mouse ports, network cable port, microphone/speaker/auxiliary input portsand printer port (SCSI or Parallel). There's also a place for the power cord plug.•The monitor, which resembles a television, is where the computer displays text and pictures. Parts of the Computer•The mouseis the hand-held device that lets you point, click, and move objects on the monitor screen. Some models have a ball underneath which allows you to easily move it on a flat surface. The mouse got its name because of its size and shape. •Typically, a mouse has two or three buttons used to move a cursor around the screen. You will learn more about using the mouse in Lesson 2.•The keyboardlets you type information into the computer. It resembles a typewriter keyboard.Input Devices•Input devices are connected to the computer through ports or sockets. Some of these peripheral devices are used to enter information into the computer. They include keyboards, scanners, joysticksand digital cameras. •Let's look more closely at these tools: The Keyboard•The main part of a computer keyboardhas alpha-numeric(letter and number) keys similar to a typewriter. However, the keyboard also features keys that cause the computer to perform specific tasks. The Mouse•The mouseis the hand-held device that lets you pointto objects on the screen, clickon them, and movethem.Output Devices•Output devices, such as computer monitors, deliver information to the user. Speakers, earphones, and printersare also output devices. They allow you to hear sound and print pages, respectively.Printers•There are three main types of printers:•Dot matrix printers produce characters and illustrations by striking pins against an ink ribbon. It's the least expensive printer and doesn't provide the same high quality as that of an ink jet or laser jet printer. However, it can print multi-page forms -a task laser and inkjet printers can't do.•Ink jetprinters shoot tiny drops of ink onto paper. They provide good quality printing and can print in color.•A laserprinter usually costs more than an inkjet. It produces better quality black text documents and usually turns out more pages at a lower cost per page than inkjets.Monitors•The monitorworks with a video card, located inside the computer case, to allow you to see images and text on the screen. Monitors come in different sizes, including 15, 17, 19 and 21-inch. Most new computers come with a monitor the size of a small TV. However, you can buy a less bulky but more expensive flat panel monitor.•Your monitor has anon/off buttonand control buttons(visible or behind a small panel) that allow you to change your monitor's display. To sharpen, brighten or center your display, check the manual that came with your monitor.Modem Plays Dual Role•The modem, used for inputand output, lets you communicate with other computers through phone lines. For example, a modem allows your computer to connect to the Internet, so you can see this module and send email. Most modems come with fax capabilities and are available in different speeds.•56K modemsare the fastest type of modem you can use on a standard phone line. Computer users who want more speed may replace a dial-up modem with a cable Internet connection or DSL Internet connection. •A cable modemallows you to connect your computer to a local cable television line and is about 26 times faster than a standard 56K phone modem. It is nearly equal to the data rate available to a DSL subscriber. A cable modem can be added to or integrated with a set-top box that provides your TV set with channels for Internet access. In most cases, cable modems are furnished as part of the cable access service and are not bought directly and installed by the subscriber. Computer Parts -InsideMotherboards and Expansion Cards•How a computer handles information depends largely on its inner parts. •Here are some of the components that make your computer work:•The motherboardis the computers main circuit board. It's a thin plate that holds the CPU (Central Processing Unit), memory, and expansion cards to control the video, audio and more. The motherboard connects directly or indirectly to every part of the computer.•An expansion card is a card which you can install to expand a computer's capabilities. For example, your computer's video cardis an expansion card which plugs into the motherboard.•The sound card, also called an audio card, is another type of expansion card. It lets the computer play sounds through speakers. Some motherboards feature integrated sound, and do not require a separate sound card..The Central Processing Unit•The Central Processing Unit (CPU), called a microprocessor, is the brain of the computer. Its job is to carry out commands. Whenever you press a key, click the mouse, or start an application, you're sending instructions to the CPU. Located inside the computer case, this silicon chipis about the size of a fingernail. •The microprocessor determines how fast a computer can execute instructions. A microprocessor's speed is measured in megahertz (MHZ), or millions of instructions per second. So, the higher the megahertz, the faster the computer can process instructions.•Intel, Cyrix and AMD are the three main CPU manufacturers for PCs. The PowerPC microprocessor, developed by Apple, Motorola, and IBM, is used in Macintosh personal computers.Storing Information•RAM (Random Access Memory)is your system's short-term memory. Data is temporarily stored here until you save your work to the hard disk. •This short-term memory disappears when the computer is turned off, so always save your file before turning off the machine. When you save a file, you are saving it to long-term storage.•The more RAM you have, the faster you computer performs. RAM is measured in megabytes(MB) or gigabytes(GB). •To understand megabytes and gigabytes, you need to know about bits and bytes. A bit is the smallest unit of data in computer processing. A byte is a group of eight bits. A megabyte is about one million bytes. A gigabyte is 1,024 megabytes.•To put this into perspective, consider that a printed page of single-spaced text contains about 3,000 characters. One MB holds about 400 pages of single-spaced text.More About Storing InformationThe hard disk drive(also called the hard disk) on your computer is where information isstored permanently. This islong-term storage.When you use a word processing program, the computer loads the instructions from long-term storage (your hard disk) into short-term memory.The hard disk driveis the data center inside of the computer. All of your programs are stored here. Hard disk speed determines how fast your computer starts up and loads programs. The hard disk is called the C drive on most computers.CD-Rom Drives and More•A CD-ROM (Compact Disk Read-Only Memory)drive accesses information on a CD-ROM similar to how a CD player accesses music from a CD. CD-ROMs hold much more information than floppy disks -up to 650 MB or the equivalent of about 450 average size books•ROM (Read-only memory)means you can access the programs or data stored on CD-ROMs but you can't write or store your own data or programs on them. (Recording information on a compact disk requires a special type of drive.) •A CD writeris a device that can write CD-RW (Compact Disk ReWritable) and CD-R (Compact Disk-Recordable) discs, and read CD-ROM discs. CD-RW discs may be written, erased and rewritten, while CD-R discs may be written only once. The terms CD-RW and CD-R may also refer to the CD writer itself. •DVD-ROM (Digital Versatile Disc Read-Only Memory), refers to the DVD media itself, or to the disk drive. DVD-ROM drives can read DVD discs, all types of CDs, and can display movies from digital video discs.•A Zip drivestores 250 megabytes on disks similar to floppy disks, but Zip drives cannot read or write standard floppy disks. What is Software? •When you want your computer to perform a task, you give it instructions using software. Softwareis the name for the applicationsor programsthat run on your computer.•Two common types of software are system software and application software.•Theoperating system (OS)or system softwareis the most important program that runs on a PC. Operating systems recognize input from the keyboard, send output to the monitor, keep track of files and directories, and control peripheral devices such as printers. •An operating system lets you use different types of application software. For example, you can use a word processing application to write a letter, and a spreadsheet application to track your financial information. To learn more about operating systems, see the Learning module on Windows XP. To learn more about applications, see the Learning modules on Word, Excel, PowerPoint and Access.Licensing Basics•When you buy software, you are actually buying a license to use the product, not the programs themselves. •A software product license gives you the legal right to run a software program on your computer. When you buy software at a store, the license comes in the box or appears online when you install the software. •To use the software legally, you must comply with the End User License Agreement (EULA). That's the agreement that appears during the installation process.•When you buy a new computer, software may be pre-installed.•Some software companies offer volume licensing or volume purchasing. An organization can save a lot of money if they choose to buy multiple product licenses. The licensing options vary, depending on the product and the size and type of organization. Software Piracy•Software piracyis the illegal distribution and/or copying of software for personal or business use. While it may not seem like a big deal, sharing software with others violates federal copyright law. •End-User copyingis one of the most common forms of software piracy. It typically involves friends loaning disks to each other or organizations not reporting the total number of software installations on computers. •Counterfeiting, or extensive duplication and distribution of illegally copied software, is another form of software piracy. Consumers who buy counterfeit software get no warranty, no technical support and no legal right to use the software. It can even carry viruses.•Penalties for software piracy can range from fines or imprisonment of up to five years.Types of Licenses•Freeware(public domain) -This is a license that allows you to use a program at no cost. Freeware is copyrighted software that you can download, use, and legally pass around to others. •Shareware-This license allows you to download and sample shareware for a trial period. If you continue to use the program, you must reimburse the producer of the program as noted on the documentation that comes with the program. Shareware is copyrighted and includes games, screensavers, utilities, word processors, and more.•Single-user license-When you buy the product, this license grants you use of the program. This license is typical for a home user.•A multiple-user license-This license is intended to be used in a network or multiple-installation situation. Network versions are installed on a server and may allow a specified number of users to access the programs concurrently. In a multiple installation situation, a certain number of copies are installed on several machines. This is a standard license for a business or organization.•A site licenseprovides for the unrestricted installation of the software on computers owned by the purchasing site. Universities often use site licenses. Software Upgrade•Those who have purchased a software license agreement may want to upgrade the software at some point. A software upgradeis software that typically includes new and enhanced features to simplify computer tasks. If you are considering an upgrade, do research and decide if you need and can afford these features. Visit the software manufacturer's website, read PC magazine reviews, and/or visit a computer store to see the product in action. •Some upgrades are free, while others require a fee. An upgrade costs less than the full version of the software.Help the Installation Go Smoothly•The installation of new software can be as complicated as you choose to make it. What you do before the actual installation plays a major role. Follow the tips to make the process go smoothly.•First, don't try to install new software while you have many other applications running. Close all applications, close your anti-virus program and shut down your Internet connection.•If you are downloading software from the Internet, make sure you scan it for viruses first.•Always back upor copy your files to a CD or suitable storage device so that they will be recovered if your computer fails. If you unsure about this ask some one who knows. While backing up is usually routine for businesses, personal computer users often neglect this necessary taskThe Installation•The process of installing new software varies based on the software. However, most applications feature on-screen instructions. For example, you can install a new Windows application using the automated Setupprogram included in most programs. •To install a Windows application:•Insert the installation CDin the CD-ROM drive(or another drive that reads CDs). •The setup program starts automatically. •Click the Installbutton. •Follow the on-screen instructions to complete the installation. •OR•If it doesn't start automatically, you will have to launch theSetup programmanually. •Click Start. •Choose Run. •Type a:\setupif using a floppy disk, or d:\setup if using the CD-ROM drive, in the Rundialog box. •Click OK. Giving Your Computer a Long Life•Cleaning your computer and doing preventive maintenance, such as scanning for viruses, helps keep it running smoothly. •Avoiding problems saves you moneyin the long run -cutting down on the amount of money you spend for new components or repairs. •Preventative maintenance saves you timesince it saves you the hassle of dealing with systems failures and data loss. •Before attempting any of the cleaning methods or maintenance, please check with the computer manufacturer for its recommendations on proper cleaning and maintenance.Keep it Cool and Neat•Don't restrict the airflowaround your computer. Since it generates a lot of heat, an internal fan cools your computer. Dust and dirt can cause the fan to fail. So, avoid putting your computer in an area with a lot of dust and don't stack papers, books or other items on or around your computer.•If your keyboard keysget dirty, you can clean them with rubbing alcohol. Pour the alcohol onto a paper towel or anti-static wipe -not directly on the surface you want to clean.•Make sure to turn off your PC and unplug it before doing this or any of the cleaning described in this module.•Remember, dust is your computer's enemy. Use an anti-staticwipe to lightly dust your monitor and surfaces. Don't usefurniture cleaners or strong solvents.•Use a can ofcompressed airwith a narrow nozzle to blow out debris from between the keyboard keys and the air intake slots.Disk Cleanup•When you install software, operate programs, and surf the Internet, temporary files are created. These files can clutter your computer and slow it down. Windows comes with a Disk Cleanuputility that removes temporary files and empties the Recycle Bin. Clearing out these files helps free up valuable hard disk space.Disk Cleanup•To use Windows Disk Cleanup:•Click Start. •Choose ProgramsAccessoriesSystem ToolsDisk Cleanup. •The Select Drivedialog box asks you to "Select the drive you want to clean up." •TheC: driveis usually selected by default. •Click OKto accept DRIVE_C (C:). •The Disk Cleanup for DRIVE_C (C:) dialog box appears. •Select Temporary Internet Files, Temporary Filesand/or Recycle Bin. •Click OKand the temp files you selected will be cleaned up. •Many other utilities are available to clean up your hard disk including CleanIt! and CleanWin. Most are freeware or sharewareDeleting Files•To keep your computer running smoothly, it's OK to delete, or erase, unused files. For example, you may want to delete a flyer you created for a yard sale two years ago. However, don't delete files haphazardly. Some files may be too important to get rid of.•Like Disk Cleanup, deleting files helps free up valuable hard disk space. •To delete a file:•Put unwanted files or folders in the Recycle Bin, the desktop icon that resembles a wastebasket. •OR•Right-clickon it and choose Delete. •To learn moreabout using the Recycle Binand recovering items from the Recycle Bin, see the Windows XP Lesson.Uninstalling Software•Unused software programs can also take up lots of space on your computer's hard disk. If the hard drive is close to being full, problems can result. •To improve computer performance, you can uninstallunused or unwanted software. To simplify this process, Windows comes with an uninstall functioncalled the Add/Remove Programs Wizard.•To use this wizard: •Click Start. •Choose Settings Control Panel. •Open Add/Remove Programs. •When theAdd/Remove Program Propertiesdialog box appears, select the program you want to remove. •Click Add/Remove. •Answer any other promptsthe wizard displays for removing the program. Some programs, such as Microsoft Word, may require you to insert the original installation disks or CD to uninstall. •After the uninstall process is complete, choose Cancelto close the Add/Remove Programs Propertiesdialog box. •Close the Control Panel. What is ScanDisk?•ScanDiskis a program that repairs errors on your computer drives.•If you turn your computer off before you go through the Shut Down process, the computer will automatically run ScanDisk when it starts up again. So, if you've ever turned your computer on after your system has crashed, you've seen Scandisk at work. The message reads, in part, "ScanDisk is now checking drive C for errors."•You can also run the utility on your own. Preparing to Use ScanDisk•Before using ScanDisk, close all programs that are running.•To close all programs:•Press Ctrl + Alt + Deleteon your computer keyboard. •Click each item to highlight it and then click End Taskfor each program except for Windows Explorerand Systray. •You must do this for each program one at a time until they are closed. Using ScanDisk•Now that you've closed all programs, you are ready to use ScanDisk.•To use ScanDisk:•Click Start. •Choose Programs Accessories System Tools Scandisk. •When the ScanDiskdialog box appears, select the C: drive. •Choose Thoroughor Standard. •If you choose Thorough, you can click Optionsfor scanning: •1.Area of disk to scan. Choose what part of the disk you want to scan. The defaults are usually OK for this. •2. Do not perform write-testing. Check to see if each sector of the disk can be successfully written to. Keep this unchecked.•3. Do not repair bad sectors in hidden and system files. ScanDisk will not scan hidden or system files. •It may be best to chooseAutomatically fix errors. •Click OKto run ScanDisk. Defragmenting•As you install more and more software, your hard drive may become fragmented. Fragmentationis the spreading of parts of files over the hard drive. It can decrease the speed at which programs are loaded.•Defragmentingrearranges program files so programs can start faster.•Windows operating systems come with the freeDisk Defragmentertool. You can buy other defragment tools, such as Norton Utilities Speed Disk, that can also do the job.•Depending on the size of your drives and the number of files and programs on your computer, a defragmenter can take time to do its job.Using the Disk Defragmenter•Now that you've closed all programs, you are ready to defragment your disk.•To defragment your disk:•Click Start. •Choose Programs Accessories System Tools Disk Defragmenter . •When the Select Drivedialog box appears, select the •Click OK. •Defragment of the drive you selected begins automatically. A bar in theDisk Defragmenter dialog box shows the progress. You will receive a message when the process is complete. •Remember: Don't run any programs, surf the Internet or do any work on your machine while the defragmenter is running.What is Backup?•Backupis the process of copying files so they will be saved in the case of computer failure or other problem. The retrieval of files that have been backed up is called restoring.•Many computers come with basic backup software, but you can also buy backup software if needed. Some backup tools are more reliable and easier to use than others. Do some research and find out what best meets your needs.Backup Methods•How you backup your files and how you store that backup is important.•There are two basic backup methods:•1. Local backupis good practice, especially for people who use their computers to keep track of personal financial information. If your computer crashes, having backup files allows you to reconstruct your records. Depending on your hardware and the size of your files, use floppy disks, zip disks, or CD-Rsto perform a local backup•Make sure you store disks in a safe place,such as a fireproof safe box.•Your storage area should offer protection from such hazards as temperature, moisture, dirt, and magnetic fields. For example, a plastic box kept on a sunny windowsill is a bad idea.•Finally, consider off-site storage. This allows for safeguarding against total disaster (for example, tornado or hurricane). •2. Internet backupallows you to upload your files to another site for safekeeping. If your computer crashes, you'll be able to download them from this site. Internet backup services allow you to save by folder or file type for a monthly fee. If you're interested in this option, do some Internet research to find storage sites.Using Microsoft Backup•Your PC probably came with a backup tool called Microsoft Backup. Use the Microsoft Backup Wizardto tell your computer how, what and where to backup your files.•To use Microsoft Backup:•Click Start. •Choose Programs Accessories System Tools Backup. •TheMicrosoft Backupdialog box appears asking, What would you like to do? •Choose Create a new backup job•Click OK. •The Backup Wizarddialog box appears with the heading What to backup.What is a Virus?•A virus is a piece of programming code, usually disguised as something else, that causes harm to your computer. It is often designed to automatically spread to other computer users, who unknowingly spread it to others. Viruses can be transmitted as attachments to email, as downloads, or be on a disketteor CD. •Some viruses can erase data or damage your hard disk. You can take steps to protect your PC from viruses. Protect Your Computer•There are two basic steps you can take to fight computer viruses. •Never open an email attachment unless you know who sent it and what the attachment contains. •Install and use Anti-virus software to scan attachments before you open them. •Anti-virus software searches your computer for known or potential viruses, and in some products, removes any viruses that are found. •You can purchase Anti-virus software such asNorton Anti-virusand McAfee Virus Scan from Internet vendors or traditional stores. Prices and level of protection vary from product to product.•Since new viruses are created every day, keeping your computer virus-free goes beyond simply installing the software. Anti-virus software usually comes loaded with a set of virus signatures (can distinguish individual viruses) that are almost instantly outdated. Anti-virus software companies post the latest signatures, or .dat files, on their web sites. Update your virus signatures regularly by downloading these .dat files and stay protected. Maintenance Schedule•Here's an example of a maintenance schedule. Create your own to suit your needs. . Preventative Maintenance Task FrequencyAutomatic?Scan file systems for errorsdailyyesScan for virusesdailyyesBackup data dailynoClean computer screenweeklynoScan hard disk for read errorsweeklyyesDefragment hard disk weeklyyesUpdate virus signaturesweeklysometimesClean mouse monthlynoDelete unnecessary filesmonthlynoClean exterior of caseas needednoClean exterior of monitor as needednoClean keyboard as needednoCheck connections and cablesbi-annuallynoChallenges•Develop a maintenance schedule for your computer. •Create a backup schedule. Periodically copying and storing important files could save you a great deal of frustration. •If you already backup files on a regular basis, review your storage conditions. Do they need to be improved? •Following the steps outlined in this module, find how much space you have left on your computer's hard disk. •Using ScanDisk, run a Standard scan of your system. •Review the files and folders on your computer. Delete the ones you don't need. •Search the Internet and find a copy of an End User Licensing Agreement for a software application. Read it to get an idea of what this type of agreement contains. •Go to software website, pick a computer magazine or go to a computer store and learn about software. •Find out what types of drives are on your computer. CD-ROM, CD-RW, Zip Drive and/or DVD-ROM?