Computer Programmer

A programmer is someone who writes computer software. The term computer programmer can refer to a specialist in one area of computer programming or to a generalist who writes code for many kinds of software. One who practices or professes a formal approach to programming may also be known as a programmer analyst. A programmer's primary computer language (Lisp, Java, Delphi, C++, etc.) is often prefixed to the above titles, and those who work in a web environment often prefix their titles with web. The term programmer can be used to refer to a software developer, software engineer, computer scientist, or software analyst. However, members of these professions typically possess other software engineering skills, beyond programming; for this reason, the term programmer is sometimes considered an insulting or derogatory oversimplification of these other professions. This has sparked much debate amongst developers, analysts, computer scientists, programmers, and outsiders who continue to be puzzled at the subtle differences in these occupations.
Those proficient in computer programming skills may become famous, though this regard is normally limited to software engineering circles. Ada Lovelace is popularly credited as history's first programmer. She was the first to express an algorithm intended for implementation on a computer, Charles Babbage's analytical engine, in October 1842. Her work never ran, though that of Konrad Zuse did in 1941. The ENIAC programming team, consisting of Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman were the first working programmers.
International Programmers' Day is celebrated annually on January 7.
Nature of the work
Computer programmers write, test, debug, and maintain the detailed instructions, called computer programs, that computers must follow to perform their functions. Programmers also conceive, design, and test logical structures for solving problems by computer. Many technical innovations in programming — advanced computing technologies and sophisticated new languages and programming tools — have redefined the role of a programmer and elevated much of the programming work done today. Job titles and descriptions may vary, depending on the organization.
Programmers work in many settings, including corporate information technology departments, big software companies, and small service firms. Many professional programmers also work for consulting companies at client' sites as contractors. Licensing is not typically required to work as a programmer, although professional certifications are commonly held by programmers. Programming is widely considered a profession (although some authorities disagree on the grounds that only careers with legal licensing requirements count as a profession).
Programmers' work varies widely depending on the type of business they are writing programs for. For example, the instructions involved in updating financial records are very different from those required to duplicate conditions on an aircraft for pilots training in a flight simulator. Although simple programs can be written in a few hours, programs that use complex mathematical formulas whose solutions can only be approximated or that draw data from many existing systems may require more than a year of work. In most cases, several programmers work together as a team under a senior programmer’s supervision.
Programmers write programs according to the specifications determined primarily by more senior programmers and by systems analysts. After the design process is complete, it is the job of the programmer to convert that design into a logical series of instructions that the computer can follow. The programmer codes these instructions in one of many programming languages. Different programming languages are used depending on the purpose of the program. COBOL, for example, is commonly used for business applications which are run on mainframe and midrange computers, whereas Fortran is used in science and engineering. C++ is widely used for both scientific and business applications. Java, C# and PHP are popular programming languages for Web and business applications. Programmers generally know more than one programming language and, because many languages are similar, they often can learn new languages relatively easily. In practice, programmers often are referred to by the language they know, e.g. as Java programmers, or by the type of function they perform or environment in which they work: for example, database programmers, mainframe programmers, or Web developers.
When making changes to the source code that programs are made up of, programmers need to make other programmers aware of the task that the routine is to perform. They do this by inserting comments in the source code so that others can understand the program more easily. To save work, programmers often use libraries of basic code that can be modified or customized for a specific application. This approach yields more reliable and consistent programs and increases programmers' productivity by eliminating some routine steps.

Testing and debugging

Programmers test a program by running it and looking for bugs. As they are identified, the programmer usually makes the appropriate corrections, then rechecks the program until an acceptably low level and severity of bugs remain. This process is called testing and debugging. These are important parts of every programmer's job. Programmers may continue to fix these problems throughout the life of a program. Updating, repairing, modifying, and expanding existing programs sometimes called maintenance programmer. Programmers may contribute to user guides and online help, or they may work with technical writers to do such work.
Certain scenarios or execution paths may be difficult to test, in which case the programmer may elect to test by inspection which involves a human inspecting the code on the relevant execution path, perhaps hand executing the code. Test by inspection is also sometimes used as a euphemism for inadequate testing. It may be difficult to properly assess whether the term is being used euphemistically.
Application versus system programming
Computer programmers often are grouped into two broad types: application programmers and systems programmers. Application programmers write programs to handle a specific job, such as a program to track inventory within an organization. They also may revise existing packaged software or customize generic applications which are frequently purchased from independent software vendors. Systems programmers, in contrast, write programs to maintain and control computer systems software, such as operating systems and database management systems. These workers make changes in the instructions that determine how the network, workstations, and CPU of the system handle the various jobs they have been given and how they communicate with peripheral equipment such as printers and disk drives.

 Types of software

Programmers in software development companies may work directly with experts from various fields to create software — either programs designed for specific clients or packaged software for general use — ranging from computer and video games to educational software to programs for desktop publishing and financial planning. Programming of packaged software constitutes one of the most rapidly growing segments of the computer services industry.
In some organizations, particularly small ones, workers commonly known as programmer analysts are responsible for both the systems analysis and the actual programming work. The transition from a mainframe environment to one that is based primarily on personal computers (PCs) has blurred the once rigid distinction between the programmer and the user. Increasingly, adept end users are taking over many of the tasks previously performed by programmers. For example, the growing use of packaged software, such as spreadsheet and database management software packages, allows users to write simple programs to access data and perform calculations.
In addition, the rise of the Internet has made Web development a huge part of the programming field. More and more software applications nowadays are Web applications that can be used by anyone with a Web browser. Examples of such applications include the Google search service, the Hotmail e-mail service, and the Flickr photo-sharing service.


What is Program....


An organized list of instructions that, when executed, causes the computer to behave in a predetermined manner. Without programs, computers are useless.
A program is like a recipe. It contains a list of ingredients (called variables) and a list of directions (called statements) that tell the computer what to do with the variables. The variables can represent numeric data, text, or graphical images.
There are many programming languages -- C, C++, Pascal, BASIC, Java, FORTRAN, COBOL, and LISP are just a few. These are all high-level languages. One can also write programs in low-level languages called assembly languages, although this is more difficult. Low-level languages are closer to the language used by a computer, while high-level languages are closer to human languages.
Eventually, every program must be translated into a machine language that the computer can understand. This translation is performed by compilers, interpreters, and assemblers.
When you buy software, you normally buy an executable version of a program. This means that the program is already in machine language -- it has already been compiled and assembled and is ready to execute.


Various forms of Monitors



Cathode Ray Tube

Definitions

  • A cathode is a terminal or electrode at which electrons enter a system, such as an electrolytic cell or an electron tube.
  • A cathode ray is a stream of electrons leaving the negative electrode, or cathode, in a discharge tube (an electron tube that contains gas or vapor at low pressure), or emitted by a heated filament in certain electron tubes.
  • A vacuum tube is an electron tube consisting of a sealed glass or metal enclosure from which the air has been withdrawn.
  • A cathode ray tube or CRT is a specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface.
Besides television sets, cathode ray tubes are used in computer monitors, automated teller machines, video game machines, video cameras, oscilloscopes and radar displays.
The first cathode ray tube scanning device was invented by the German scientist Karl Ferdinand Braun in 1897. Braun introduced a CRT with a fluorescent screen, known as the cathode ray oscilloscope. The screen would emit a visible light when struck by a beam of electrons.
In 1907, the Russian scientist Boris Rosing (who worked with Vladimir Zworykin) used a CRT in the receiver of a television system that at the camera end made use of mirror-drum scanning. Rosing transmitted crude geometrical patterns onto the television screen and was the first inventor to do so using a CRT.
Modern phosphor screens using multiple beams of electrons have allowed CRTs to display millions of colors.

LCD

Liquid crystal display (LCD) is a thin, flat panel used for electronically displaying information such as text, images, and moving pictures. Its uses include monitors for computers, televisions, instrument panels, and other devices ranging from aircraft cockpit displays, to every-day consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones. Among its major features are its lightweight construction, its portability, and its ability to be produced in much larger screen sizes than are practical for the construction of cathode ray tube (CRT) display technology. Its low electrical power consumption enables it to be used in battery-powered electronic equipment. It is an electronically-modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome. The earliest discovery leading to the development of LCD technology, the discovery of liquid crystals, dates from 1888.[1] By 2008, worldwide sales of televisions with LCD screens had surpassed the sale of CRT units.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, and two polarizing filters, the axes of transmission of which are (in most of the cases) perpendicular to each other. With no actual liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer.

The surface of the electrodes that are in contact with the liquid crystal material are treated so as to align the liquid crystal molecules in a particular direction. This treatment typically consists of a thin polymer layer that is unidirectionally rubbed using, for example, a cloth. The direction of the liquid crystal alignment is then defined by the direction of rubbing. Electrodes are made of a transparent conductor called Indium Tin Oxide (ITO).

Before applying an electric field, the orientation of the liquid crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic device (still the most common liquid crystal device), the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This reduces the rotation of the polarization of the incident light, and the device appears grey. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

The optical effect of a twisted nematic device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, these devices are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). These devices can also be operated between parallel polarizers, in which case the bright and dark states are reversed. The voltage-off dark state in this configuration appears blotchy, however, because of small variations of thickness across the device.

Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).

When a large number of pixels are needed in a display, it is not technically possible to drive each directly since then each pixel would require independent electrodes. Instead, the display is multiplexed. In a multiplexed display, electrodes on one side of the display are grouped and wired together (typically in columns), and each group gets its own voltage source. On the other side, the electrodes are also grouped (typically in rows), with each group getting a voltage sink. The groups are designed so each pixel has a unique, unshared combination of source and sink. The electronics, or the software driving the electronics then turns on sinks in sequence, and drives sources for the pixels of each sink.
 

Gas Plasma Displays 
An overview of plasma displays


Gas plasma technology is a new way to build video and computer monitors. Essentially plasma units have the brightness and look of a CRT monitor, but they offer a much larger image and are thin enough and light enough to hang on any wall. This combination makes them ideal where lighting conditions would favor a monitor, but audience size indicates a projector. Like LCD displays, plasma monitors do not exhibit the distortion and loss of clarity in the corners inherent to CRTs.
How do plasma monitors work?
Plasma monitors work much like CRT monitors, but instead of using a single CRT surface coated with phosphors, they use a flat, lightweight surface covered with a matrix of millions of tiny glass bubbles, each having a phosphor coating. These phospors are caused to glow in the correct pattern to create an image.
What are the advantages of plasma?
Plasma monitors have several advantages over CRT-based monitors:
  • Thin and lightweight: at only 4" - 6" thick and about 60-100 lbs., they’re easy to hang on any wall.
  • Very bright: less sensitive to ambient light than most LCD projectors, plasma monitors have the brightness and contrast of CRT-based sets.
  • 160° viewing cone: ideal when your room is wide and people may view the monitor from farther off-axis than normal.
  • Stable and distortion-free: unaffected by magnetic fields; useful in many applications where CRT monitors or LCD and CRT projectors are problematic. Entire image always in perfect focus, not just in the center, but all the way to the corners.
  • Look and feel: plasma somehow looks different--better--than monitors and projectors alike. It's hard to quantify that difference, but most people would say they have more depth and warmth than other types media. They look very, very good.
What are the disadvantages of plasma?
This new technology has several disadvantages worth mentioning.
  • Cost: plasma is expensive. For that reason alone, plasma is not for everyone. But prices are coming down, as they do for most new technologies.
  • More susceptible to burn-in than CRT monitors. It's not a good medium on which to display a company logo for two or three hours at a time. But with the appropriate precautions, and in some situations a screen saver, you should not expect problems.
  • Resolution restrictions: plasma is subject to the same type of resolution problems as LCD or DLP projectors. You'll get the best images when the resolution of your source matches the "true" resolution of the monitor. But, as with LCD, the monitors will incorporate compression or expansion circuitry to automatically resize other resolution sources to match their native resolution, and most people will be very happy with the result. Still, if sharpness is critical for your application and you'll be using a variety of computer sources, you may be better off with a CRT-based unit.
  • Doesn't travel well: plasma is not portable. These monitors weigh 60 - 100 pounds and they don't do well if you drop them. If you want to travel with a plasma monitor, plan to invest in a good shipping case.
There's one other rumored "problem" with plasma that turns out not to be true. It has been said by some that plasma units do not have a long lifespan. Actually, the estimated life span for plasma monitors (according to Sony) is about 30,000 hours-- which translates to approximately 15 years at 8 hours a day, 5 days a week (comparable, or maybe a bit better, than a CRT-based monitor).



Satellite TV On PC

Technology is advancing so fast that now one can watch satellite TV or hear radio on a home PC. All you need is special hardware known as PCTV cards that are of two kinds. One kind needs to be installed in the PC while the other kind is an external box that plugs into the PC’s USB port.
There are cards that use the PC’s infrastructure to decode satellite signals and allow users to enjoy free-to-air digital television and radio programs. There are cards that have built-in processors that allow TV viewing in a separate window while the PC runs other programs. Both kinds of cards can be utilized to receive Broadband Internet via Satellite. Requests are made using a telephone line but data is received at 40MB per second via the satellite dish.
To view satellite TV on your PC you would require a minimum processor that is Pentium II 333 MHz, an operating system like Microsoft Windows 98/ME/2000/XP, as well as hardware consisting of sound card, spare USB slot, and a CD Rom drive. If you are a computer geek you could in addition to the cards have a Windows media player, real player, or quick time player all of which will take you to the next level of viewership.
The options are many. The PC can be directly connected to a satellite dish by using a product like Hauppauge 3000 or through the Internet cable; or via the satellite box (run an aerial lead from the RF output socket of the Shy Digibox to the input aerial socket on a standard PC TV card or USB TV adapter). Direct TV and Dish TV both recommend using a connection via their proprietary satellite TV receiver box as ideal.
With a PC-TV-Radio one can simultaneously or alternately watch regular TV, a movie, or sports, and enjoy crystal clear music while writing, checking mail, telewebbing, or surfing the Internet. The options are astounding one can download and record favorite programs, record music, and be creative.
Free Satellite TV provides detailed information on Free Satellite TV, Free Satellite TV Systems, Free Satellite TV on PC, Free Satellite TV Offers and more. Free Satellite TV is affiliated with Dish Satellite Network.

Changing MAC address In Windows XP/Vista and Linux

I guess you've never heard of this tutorial, but I am here just to repeat it.
Ok go directly to the problem...!!!!

There are two ways change MAC address on Windows.

Method #1: Changing MAC address by changing NIC properties from Device Management System.

This is depending on the type of Network Interface Card (NIC) you have. If you have a card that doesn’t support Clone MAC address, then you have to go to second method.

a) Go to Start->Settings->Control Panel and double click on Network and Dial-up Connections.

b) Right click on the NIC you want to change the MAC address and click on properties.

c) Under "General" tab, click on the "Configure" button

d) Click on "Advanced" tab

e) Under "Property section", you should see an item called "Network Address" or "Locally Administered Address", click on it.









f) On the right side, under "Value", type in the New MAC address you want to assign to your NIC. Usually this value is entered without the "-" between the MAC address numbers.

g) Goto command prompt and type in "ipconfig /all" or "net config rdr" to verify the changes. If the changes are not materialized, then use the second method.

h) If successful, reboot your system.

Method #2: This should work on all Windows 2000/XP/Vista systems

a) Go to Start -> Run, type "regedt32" to start registry editor. Do not use "Regedit".

b) Go to "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}". Double click on it to expand the tree. The subkeys are 4-digit numbers, which represent particular network adapters. You should see it starts with 0000, then 0001, 0002, 0003 and so on.

c) Find the interface you want by searching for the proper "DriverDesc" key.

d) Edit, or add, the string key "NetworkAddress" (has the data type "REG_SZ") to contain the new MAC address.

e) Disable then re-enable the network interface that you changed (or reboot the system).

Getting MAC address from command line

a) Go to Start -> Run (or win key   R) type "cmd" then press Enter.

b) type "getmac" at the console window. Windows will show you MAC address of all NIC (ethernet and wireless) NIC on your computer.

Spoof MAC address in Linux
To change/clone your MAC address in Linux (and most *nix system) is very easy to do. All it takes is two easy to script commands:

ifconfig eth0 down hw ether 01:02:10:B0:80:A1
ifconfig eth0 up

eth0 = enthernet 0
01:02:10:B0:80:A1 = new MAC address you want to change to.

Yes, it is very easy to change MAC address without use any third party script/application. You can change your MAC address anytime that you need.

good luck and success, do not never feel bored to increase knowledge
!!!!

Compression, Encryption, Deduplication, and Replication: Strange Bedfellows

One of the great ironies of storage technology is the inverse relationship between efficiency and security: Adding performance or reducing storage requirements almost always results in reducing the confidentiality, integrity, or availability of a system.

Many of the advances in capacity utilization put into production over the last few years rely on deduplication of data. This key technology has moved from basic compression tools to take on challenges in the fields of replication and archiving, and is even moving into primary storage. At the same time, interconnectedness and the digital revolution has made security a greater challenge, with focus and attention turning to encryption and authentication to prevent identity theft or worse crimes. The only problem is, most encryption schemes are incompatible with compression or deduplication of data!

Incompatibility of Encryption and Compression

Consider a basic lossless compression algorithm: We take an input file consisting of binary data and replace all repeating patterns with a unique code. If a file contained the sequence, “101110″ eight hundred times in a row, we could replace the whole 4800-bit sequence with a much smaller sequence that says “repeat this eight hundred times”. In fact, this is exactly what I did (using English) in the previous sentence! This basic concept, called run-length encoding, illustrates how most modern compression technology functions.
Replace the sequence of identical bits with a larger block of data or an entire file and you have deduplication and single-instance storage! In fact, as the compression technology gains access to the underlying data, it can become more and more efficient. The software from Ocarina, for example, actually decompresses jpg and pdf files before recompressing them, resulting in astonishing capacity gains!

Now let’s look at compression’s secretive cousin, encryption. It’s only a small intellectual leap to use similar ideas to hide the contents of a file, rather than just squashing it. But encryption algorithms are constantly under attack, so some very smart minds have come up with some incredibly clever methods to hide data. One of the most important advances was public-key cryptography, where two different keys are used: A public key used for writing, and a private key to read data. This same technique can be used to authenticate identity, since only the designated reader would (in theory) have the key required.
Cryptography has become exceedingly complicated lately in response to repeated attacks. Most compression and encryption algorithms are deterministic, meaning that identical input always yields the same output. This is unacceptable for strong encryption, since a known plaintext attack can be used with the public key to reveal the contents. Much work has focused on eliminating residues of the original data from the encrypted version, as illustrated brilliantly on Wikipedia with the classic Linux “tux” image. The goal is to make the encrypted data indistinguishable from random “noise”.
What happens when we mix these powerful technologies? Deduplication and encryption defeat each other! Deduplication must have access to repeating, deterministic data, and encryption must not allow this to happen. The most common solution (apart from skipping the encryption) is to place the deduplication technology first, allowing it access to the raw data before sending it on to be encrypted. But this leaves the data unprotected longer, and limits the possible locations where encryption technology can be applied. For example, an archive platform would have to encrypt data internally, since many now include deduplication as an integral component.
Why do we prefer compression to encryption? Simply because that’s where the money is! If we can cut down on storage space or WAN bandwidth, we see cost avoidance or even real cost savings! But if we “waste” space by encrypting data, we only save money in the case of a security breach.

A Glimmer of Hope

I had long thought this was an intractable problem, but a glimmer of hope recently presented itself. My hosting provider allows users to back up their files to a special repository using the rsync protocol. This is pretty handy, as you can imagine, but I was concerned about the security of this service. What happens if someone gains access to all of my data by hacking their servers?
At first, I only stored non-sensitive data on the backup site, but this limited its appeal. So I went looking for something that would allow me to encrypt my data before uploading it, and I discovered two interesting concepts: rsyncrypto and gzip-rsyncable.
rsync is a solid protocol, reducing network demands by only sending the changed blocks of a file. But, as noted, compression and encryption tools change the whole file even if only a tiny bit has been altered. A few years back, the folks behind rsync (who also happen to be the minds behind the Samba CIFS server) developed a patch for gzip which causes it to compress files in chunks rather than in their entirety. This patch, called gzip-rsyncable, hasn’t been added to the main source even after a dozen years, but yields amazing results in accelerating rsync performance.
The same technique was then applied to RSA and AES cryptography to create rsyncrypto. This open source encryption tool makes a simple tweak to the standard CBC encryption schema (reusing the initialization vector) to allow encrypted files to be sent more efficiently over rsync. In fact, it relies on gzip-rsyncable to work its magic. Of course, the resulting file is somewhat less secure, but it is probably more than enough to keep a casual snooper at bay.
Both of these tools are similar to modern deduplication techniques in that they chop files up into smaller, variable-sized blocks before working their magic. And the result is awesome: I modified a single word in a large word document that I had previously encrypted and stored at the backup site and was able to transfer just a single block of the new file in an instant rather than a few minutes. My only real issue is the lack of integration of all of these tools: I had to write a bash script to encrypt  my files to a temporary directory before rsyncing them. I wish they could be integrated with the main gzip and rsync sources!
If you are interested in trying out these tools for yourself, and if you use a Mac, you are in luck: Macports offers both tools as simple downloads! Just install macports, type “sudo port install gzip +rsyncable” to install gzip with the –rsyncable flag, then type “sudo port install rsyncrypto” and you’re done! I’ll post more details here if there is interest.

Ref : http://blog.fosketts.net/2009/02/05/compression-encryption-deduplication-replication/

Computer Viruses


A virus is a program designed by a computer programmer (malicious hacker) to do a certain unwanted function. The virus program can be simply annoying like displaying a happy face on the user's screen at a certain time and date. It can also be very destructive and damage your computer's programs and files causing the computer to stop working.
The reason why hackers create viruses are open for speculation. The most quoted reason is simply to see if it can be done. Other reasons are Ludite based "smash the machine" motivations, antiestablishment/anti-corporate actions, criminal intent, and various others that range into the "conspiracy theory" realm.
Viruses take two basic forms
One is a boot sector viruses which infect the section of a disk that is first read by the computer. This type of virus infects the boot or master section of any disks that it comes in contact with. The second is a program virus that infects other programs when the infected program is run or executed. Some viruses infect both and others change themselves (polymorphic) depending on the programs they encounter.
Though viruses do not damage computer hardware there have been attempts to create programs that will do things like run the hard drive until it fails or lodge itself in the computer's clock (which has a rechargeable battery) allowing it to remain active even months after the computer has been unplugged. Other viruses affect certain microchips (BIOS chip for instance). These microchips need to be modified under normal computer use but the virus program can produce changes which cause them to fail. Other viruses will affect the characters or images displayed on the screen which may give the impression of monitor failure.
Viruses can cause a great deal of damage to the computers it infects and can cost a lot of time and money to correct it.
Computer viruses have been around for a long time, even before computers became widely used and they will likely remain with us forever. For that reason computer users will always need ways to protect themselves from virus programs. The main, common feature of a virus is that it is contagious! Their sole purpose is to spread and infect other computers.
A computer gets a virus from an infected file.
The virus might attach themselves to a game, a program (both shareware and commercial) or a file downloaded from a bulletin board or the Internet.
You cannot get a virus from a plain email message or from a simple text file! That is because the virus needs to be 'run' or executed before it can take effect. This usually happens when the user tries to open an infected program, accesses an infected disk or opens a file with an infected macro or script attached to it. A plain email message is made up of text which does not execute or run when opened.
Modern email programs provide the ability to allow users to format email messages with HTML and attach scripts to them for various purposes and it is possible for a malicious hacker to attempt to spread a virus by building a virus script into an HTML type of email message.
When you are accepting software or scripts on Internet sites or reading mail from unknown senders it is best not to run a program from that site or sender without checking it with an anti-virus program first.
Protect yourself
You can take safeguards against virus infection. The first thing is to get an anti-virus program. Most reputable companies that create virus protection programs release an evaluation copy that an Internet user can download for free and use for a certain amount of time. This anti-virus program will be able to check your computer for viruses and repair damage or delete files that are infected with viruses. You may have to replace infected files that cannot be repaired.
The second thing you can do is purchase a copy of the program. The reason for this is that viruses are constantly being created. When you purchase an anti-virus program you are also purchasing periodical updates which keep your anti-virus program up-to-date and able to deal with new viruses as they are encountered. Commercial virus programs also allow the user to customize when and how the program will check the computer for viruses. You will need to renew this updating service periodically.
If you find that your computer has been infected with a virus use an anti-virus program to clean your computer and make sure to check all the disks that you use. This includes all the hard drives on your computer(s) and all your floppy disks and CDs as well as any media that you save information on. Remember that the virus can easily re-infect your computer from one infected file!
If you have to reload your computer programs, use the original program disks. You may want to check your original disks before reinstalling the software. If your original disks are infected contact the distributor to get replacements.
Always take the time to ensure that your computer is properly protected. Spending money on a good virus checking program could save you hundreds of dollars and lots of time later.
A discussion of viruses would not be complete without mentioning hoaxes. Malicious people without programming skills will send out fake virus warnings causing people to take unnessary measures which often cause your computer harm. One example tries to get the unsuspecting computer user to delete an important system file by warning them that it is a virus. A legitimate virus warning will provide a link to a website operated by an anti-virus company with more information about that virus. Don't forward a virus warning until you have check out whether it is legitimate.