COMPUTER NETWORK

Two or more computers connected together through a communication media form a computer network.

 The computers are connected in a network to exchange information and data. The computers connected in a network can also use resources of other computers.

 Computer Network Components

There are different components of a network. Following are the basic components of network.

1. Server:

Powerful computers that provides services to the other computers on the network.

2. Client:

Computer that uses the services that a server provides. The client is less powerful than server.

3. Media:

A physical connection between the devices on a network.

4. Network Adopter:

Network adopter or network interface card (NIC) is a circuit board with the components necessary for sending and receiving data. It is plugged into one of the available slots on the Pc and transmission cable is attached to the connector on the NIC.

5. Resources:

Any thing available to a client on the network is considered a resource .Printers, data, fax devices and other network devices and information are resources.

6. User:

Any person that uses a client to access resources on the network.

8. Protocols:

 These are written rules used for communications. They are the languages that computers use to talk to each other on a network

Keyloggers

The term ‘keylogger’ itself is neutral, and the word describes the program’s function. Most sources define a keylogger as a software program designed to secretly monitor and log all keystrokes. This definition is not altogether correct, since a keylogger doesn’t have to be software – it can also be a device. Keylogging devices are much rarer than keylogging software, but it is important to keep their existence in mind when thinking about information security. Legitimate programs may have a keylogging function which can be used to call certain program functions using “hotkeys,” or to toggle between keyboard layouts (e.g. Keyboard Ninja). There is a lot of legitimate software which is designed to allow administrators to track what employees do throughout the day, or to allow users to track the activity of third parties on their computers. However, the ethical boundary between justified monitoring and espionage is a fine line. Legitimate software is often used deliberately to steal confidential user information such as passwords. Most modern keyloggers are considered to be legitimate software or hardware and are sold on the open market. Developers and vendors offer a long list of cases in which it would be legal and appropriate to use keyloggers, including: Parental control: parents can track what their children do on the Internet, and can opt to be notified if there are any attempts to access websites containing adult or otherwise inappropriate content; Jealous spouses or partners can use a keylogger to track the actions of their better half on the Internet if they suspect them of “virtual cheating”; Company security: tracking the use of computers for non-work-related purposes, or the use of workstations after hours; Company security: using keyloggers to track the input of key words and phrases associated with commercial information which could damage the company (materially or otherwise) if disclosed; Other security (e.g. law enforcement): using keylogger records to analyze and track incidents linked to the use of personal computers; Other reasons. However, the justifications listed above are more subjective than objective; the situations can all be resolved using other methods. Additionally, any legitimate keylogging program can still be used with malicious or criminal intent. Today, keyloggers are mainly used to steal user data relating to various online payment systems, and virus writers are constantly writing new keylogger Trojans for this very purpose. Furthermore, many keyloggers hide themselves in the system (i.e. they have rootkit functionality), which makes them fully-fledged Trojan programs. As such programs are extensively used by cyber criminals, detecting them is a priority for antivirus companies. Kaspersky Lab’s malware classification system has a dedicated category for malicious programs with keylogging functionality: Trojan-Spy. Trojan-Spy programs, as the name suggests, track user activity, save the information to the user’s hard disk and then forward it to the author or ‘master’ of the Trojan. The information collected includes keystrokes and screen-shots, used in the theft of banking data to support online fraud.

Must Use Defragmentation

De fragmentation is a process that reduces the amount of fragmentation. It does this by physically organizing the contents of the mass storage device used to store files into the smallest number of contiguous regions (fragments). It also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmentation utilities try to keep smaller files within a single directory together, as they are often accessed in sequence. Defragmentation is advantageous and relevant to file systems on electromechanical disk drives. The movement of the hard drive's read/write heads over different areas of the disk when accessing fragmented files is slower, compared to accessing the entire contents of a non-fragmented file sequentially without moving the read/write heads to seek other fragments

The Best New (OS) Operating System

Windows 8 is The Best Operating System at This Time. Windows 8 is an upcoming version of Microsoft Windows, a series of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, netbooks, tablet PCs, and media center PCs. According to unofficial sources, the release date for Windows 8 has been set for October 2012, three years after the release of its predecessor, Windows 7. Windows 8's server counterpart, Windows Server 2012, is in development concurrently with Windows 8. The most recent official pre-release version of Windows 8 is the Consumer Preview, which was released on February 29, 2012. An almost-complete Release Preview is scheduled for the first week of June 2012.

Ethical Hacking

Ethical Hacker has obtained a certification in how to look for the weaknesses and vulnerabilities in target systems and uses the same knowledge and tools as a hacker.

Fast Your Computer

Make Sure Your Hardware is Sufficient

Above and beyond everything you can do with software to optimize the function of your computer, making sure you have the proper hardware to support Windows is critical.

Clean Your Desktop

Is your Windows Desktop dotted with files? Have you noticed that your computer has been running slower and slower? Do you see the hard drive light often flashing while you wait for the computer to respond to an action? There are steps you can take to fix it. Read this article.

Scan Your Windows System for Errors

An operating system is a collection of files that perform different functions. It is possible, over time, that one or more of these system files has changed or become corrupted. If this happens, the speed of your system may decrease. By using a utility called “System File Checking”, it will inspect these files and correct any problem it finds.

Scan for Viruses, Spyware and Adware

Every Windows computer is vulnerable to viruses. Viruses are nasty little programs that cause both major and minor problems for users.

Spyware and Adware are programs created by companies to find out more information about customers, so they can better market products to them. Usually these programs are not created for malicious purposes. Spyware and Adware can load into computer memory and slow it down.

Periodically scanning and removal of Viruses, Spyware and Adware is a great way to improve computer performance.

Uninstall Unused Programs

Over time, you may have accumulated programs on your computer that you do not use. When a program is installed, it creates connections between the program and the operating system. Even if you don’t use these programs, they can slow down your system. If you have the original program’s installation disk or file, removing programs will free up space on your computer and may speed up your system's performance.

Adjust Visual Effects for Better Performance

Windows provides a number of interesting visual effects including animated windows and fading menus. If you do not have enough operating memory (see above number 1), these effects can slow down your computer. Adjusting or reducing visual effects can make a d)ifference.

To speed up Vista computers in particular you can disable features and function that are not used. For more information, read "How to Speed Up Windows Vista."

Don’t Automatically Start Programs

Programs use operating memory (RAM, also called system resources). Unless you always use these programs, you can keep them from loading at Windows startup and speed both the booting of your computer and its performance.

Defragment Your Hard Drive (After you have tried everything else)

The more information and programs you have on your computer, the more it is likely that Windows has placed parts of the same file in different locations on your hard drive. It may do this for hundreds of files and programs, depending on how much space is available. Defragmenting the hard drive places all information for each file in one place. The result can be a faster computer experience.

Important Note: Before you even try this, backup all your work onto a different computer, hard drive, CD or disk. Also, you should only do this if you have a reliable source of power for your computer. Doing this when there is a brown out or power problem in the neighborhood, is not a good idea. If a computer turns off while it is defragmenting a drive, it will create more problems than not defragmenting it in the first place.

Reinstall the Operating System and Programs

If you have done all the above steps and your computer does not become more responsive, you might consider reinstalling the operating system and programs. This is a scorched earth option - basically you backup all your data and user settings, wipe your hard drive clean and re-install the operating system with your original disks. Next, install all your favorite programs and restore all your data and user settings.

The nice thing about doing this is that you essentially have a new computer, free of years worth of software and registry changes, additions and errors that can turn a fast rabbit of a Windows computer into a slow turtle. The bad thing about this choice is that it takes time and planning to do it correctly. If your PC is 3 to 4 years old and continues to run slower than it did when you purchased it, this might be the only action that will make a significant difference.

How To Protect Your Computer

Below are some key steps to protecting your computer from intrusion:

Keep Your Firewall Turned On: A firewall helps protect your computer from hackers who might try to gain access to crash it, delete information, or even steal passwords or other sensitive information. Software firewalls are widely recommended for single computers. The software is prepackaged on some operating systems or can be purchased for individual computers. For multiple networked computers, hardware routers typically provide firewall protection.

Install or Update Your Antivirus Software: Antivirus software is designed to prevent malicious software programs from embedding on your computer. If it detects malicious code, like a virus or a worm, it works to disarm or remove it. Viruses can infect computers without users' knowledge. Most types of antivirus software can be set up to update automatically.

Install or Update Your Anti spyware Technology: Spyware is just what it sounds like—software that is surreptitiously installed on your computer to let others peer into your activities on the computer. Some spyware collects information about you without your consent or produces unwanted pop-up ads on your web browser. Some operating systems offer free spyware protection, and inexpensive software is readily available for download on the Internet or at your local computer store. Be wary of ads on the Internet offering downloadable antispyware—in some cases these products may be fake and may actually contain spyware or other malicious code. It's like buying groceries—shop where you trust.

Keep Your Operating System Up to Date: Computer operating systems are periodically updated to stay in tune with technology requirements and to fix security holes. Be sure to install the updates to ensure your computer has the latest protection.

Be Careful What You Download: Carelessly downloading e-mail attachments can circumvent even the most vigilant anti-virus software. Never open an e-mail attachment from someone you don't know, and be wary of forwarded attachments from people you do know. They may have unwittingly advanced malicious code.

Turn Off Your Computer: With the growth of high-speed Internet connections, many opt to leave theircomputers on and ready for action. The downside is that being "always on" renders computers more susceptible. Beyond firewall protection, which is designed to fend off unwanted attacks, turning thecomputer off effectively severs an attacker's connection—be it spyware or a botnet that employs yourcomputer's resources to reach out to other unwitting users

Computer Education

Computer Education

Computer Education referred to one or more courses completed by Books , Teachers , Friends & Internet that included instruction in skills incorporating the use of computer technology.