Monthly Archives: April 2016
The first computer network was set up by ARPA (Advanced Research Projects Agency), known as ARPANET in the late 1960s. It is an interconnection of many computers with the help of some network components. There are many types of networks, classified as per the geographical location of the computers and the components. The type of connection used for connecting the computers and the components used, decides the type of the computer network.
- Network Interface Cards (NIC)
Types of Computer Networking
LAN (Local Area Network)
A local area network (LAN) has computers interconnected along with some other resources, like printers, modems, floppy disks, and hard disks. LAN is restricted to a building or an office or can be a residential network connecting the computers and resources to each other. With the help of LAN, the above stated resources can be accessed and shared by all the computers in the network. The computer that manages and offers these resources is called a server computer.
MAN (Metropolitan Area Network)
The metropolitan area network is spread over an area with a diameter varying from 5 to 50 km. MAN is not owned by a single organization, instead it is an interconnection of many LANs. It has many applications and can form many networks, like the banking, military, stock brokers, and airline reservation network. All these require a lease line that is to be taken from a telephone company. The speed of the data line varies from 2 Mbps to 600 Mbps. Some MAN networks support the Internet Protocol (IP) and are called Network Service Providers (NSP). The network service provider is the backbone of the Internet Service Provider (ISP) as it connects all the ISPs. Usually, the Internet is accessed from an Internet service provider.
WAN (Wide Area Network)
The wide area network connects all the metropolitan area networks (MAN). The wide area network is a larger version of the local area network (LAN). Internet is an example of the wide area network.
GAN (Global Area Network)
The global area network comprises all the wireless LANs and satellite communication. The example of global area network is broadband global area network (BGAN) which connects all the broadband wireless voice and data communication on the earth.
Twisted pair wires, coaxial cables, and fiber optic cables are used to connect the computers and other network components together. Twisted pair wire is a telephone wire, which is used to connect the computers. Coaxial cables are the wires of the cable TV network used to connect the Internet and, in turn, to the computer network. In fiber optic technology, voice and data is transmitted in the form of light.
The wireless computer network uses the wireless technologies, like satellite communication, wireless LAN and bluetooth. The satellite uses microwaves to communicate the data and information over the network. Wireless LAN requires a router and a network adapter.
These were the types of computer networks, and their working depends on the size of the network and the type of connection used.
Computers have become almost indispensable today. However, it is after all a machine and it too needs care to remain functional all the time. So, wherever Internet technology comes into picture, computer security is a subject of major concern. This is because the PC is exposed to many viruses and malware that can harm its functioning. Computer viruses are malicious programs that start operating anonymously from any location in your system. Like biological viruses, they also replicate themselves and spread from one workstation to another in a network. They are primarily responsible for sudden deletion and corruption of files. Besides, they hamper the security of important documents stored in your system and crash your system’s RAM (Random Access Memory). Signs such as an extremely slow system, abrupt reboots, blue error screens, a lot of undefined and random errors, and a large number of pop up windows opening simultaneously, indicate a possible virus or a spyware attack! There are different types of viruses such as spyware, adware, Trojan horses, web bugs, and worms which also harm your PC. They self infest without the knowledge of your system and corrupt its sensitive data.
Methods to Get Rid of Computer Viruses
Following are methods adopted to get rid of computer viruses:
Choosing an antivirus software: Generally, an antivirus software is a part of your system as a pre-installed feature. However, the market offers you better choices always. Some of the leading antivirus software include:
Of these, Avast and AVG are some antivirus software which can be downloaded for free. McAfee and Norton are sturdy retail antivirus software of which McAfee is the oldest and Norton is the heaviest. Although Norton is one of the best antivirus programs made, its installation may slowdown the system as it is a bulky program. Nowadays, AVG is quite a popular one as it upgrades itself at regular durations without prompting the user each time.
Using online antivirus software and rescue disks: Computer viruses also keep upgrading themselves like the antivirus programs. At times, they do not let you access the antivirus software installed in your system. So what do you do? There are a few online virus scanning software that provide free online tools to tackle risky situations:
- McAfee scanner – Most recommended
- Avast Virus cleaner
- Trend Housecall
- Kaspersky online virus scanner
- Panda Activescan
Rescue disks can also help you get rid of such problems. Most antivirus software on installation, ask the user to create a ‘rescue disk’ and prompt him for reboot. Rescue disks load the antivirus software even before the operating system loads. Hence, the virus detection and removal becomes easy as the user gets access to the antivirus programs. A very crucial point to be remembered is that updation of antivirus software is as important as installing them in the system.
Using anti spyware software: Spyware are a high security risk to your system. These programs spy on your system, steal important information, and alter your system configuration. Signs of spyware attacks can be confirmed with unusual changes in web browsers, search engines, random error messages, and a very slow system. The best remedy to this problem is installation of a sturdy anti spyware software. There are many free spyware removal programs available in the market, which can be used to get rid of computer viruses. Some of the best recommended anti spyware programs are:
- Windows Defender
- Spybot search and destroy
PC Doctor and Microsoft anti spyware are also extensively used in spyware removal. Mac users can rely on MacScan.
Using anti adware software: Adware are annoying programs that are responsible for the uncontrolled number of pop up advertisements clogging your web browsers. Not only do they slow down your system, but at times they self install unnecessary software without the knowledge of the system. For removal of adware, Lavasoft’s Ad-adware is the best!
Using firewall to get rid of computer viruses: Firewalls are either hardware or software, and sometimes a combination of both. They regulate network traffic by monitoring port activity of the system based on a set of pre-defined security policies. These policies list IP addresses and ports to be blocked or allowed based on the risk proposed. Some of the best firewall products available in the market are:
- Online Armor Personal Firewall
- Comodo Internet Security
- Little Snitch
- Zone Alarm Free Firewall
- PC Tools Firewall
- Ashampoo Firewall
Of these, Zone Alarm Free Firewall is the best, as it has been going sturdy for years now without any major upgrades.
So, whenever there is a slightest doubt of a possible virus attack, there are some immediate action items to confirm your doubts!
- Stop working. Save the necessary documents and close all the windows.
- Don’t start deleting files frantically assuming the worst. Stay calm and take a backup of all the important data.
- Run your antivirus software immediately. In case it asks for any updations, update the software and run it.
- If problems persist, there is a possibility that the system is under a virus/spyware attack.
Some Tips for Intelligent Browsing
- Browse intelligently. Internet is a web of networks. Hence, the system is always prone to virus attacks. Do not visit sites that might be a source of malicious content.
- Be careful when going for free software downloads, as most of them contain spyware.
- Maintain secure browser settings every time you access your system. Nowadays, every browser gives users the convenience to adjust browser security settings. Go to Tools and access the security tab to alter browser settings if needed. You may also adjust the settings such that cookies get stored only for secure websites.
- Firewalls are a must for your system when it comes to network security. However, nowadays, Apple’s MAC OS and Windows XP have inbuilt firewall programs.
- Read online license agreements, privacy statements, and security warnings before you download any software. Agreeing under sheer carelessness and ignorance can invite malware. In such cases, consult the IT service center or make use of a search engine to check if any form of malware has been reported for the software you want to download. These measures will prevent your system from getting infected with spyware carriers like Kazaa and Grokster.
- Do not open unsolicited email attachments containing word documents and Powerpoint presentations. These are gateways to install viruses in your system. Also, be cautious while clicking on online messages claiming to alert you about your system security risk. Most of the time, they are links for installation of spyware.
- Spyware threat is obvious in case of peer-to-peer file-sharing services. So, it is advised not to download any executable files from such shared connections.
- Last but not the least, update antivirus and firewall software regularly. Most of them today are self programmed to update themselves after a specific duration.
Prevention is better than cure does not apply to health alone. It is always better to prevent the enemy from attacking, rather than letting the enemy attack and then fighting back. Upgrade your system with the latest antivirus software today!
If you are thinking of working from home, then you are not alone. Most people like working from home, using their own PC. But the question arises; how do you make money from home with a computer?
There are several ways to go about this, but you need to give it a thought with a clear mind. You have to also be aware of the many scams floating online. There may be several websites which promise a lot of money if you register with them for a small fee. You need to be careful, as several are scams. But having said that, there are others which are genuine too.
Besides these websites, you can also make money through affiliate marketing, product reviews, freelance jobs, telemarketing, and selling things online. Let’s have a look at the options in more detail.
If you already have a website or a blog, one of the best things to do is Internet affiliate marketing. The concept of affiliate marketing is that, you would be responsible for marketing a particular product or website through your blog or website, and in return, you are paid a commission. You would need to promote the services of that particular website in your blog, besides providing a link, which would direct the readers to the website you are promoting. And once the end users register for the product you are promoting, you are paid a commission.
Product Reviews and Videos
If you are good at writing, you can opt to write reviews of products. Several websites market a variety of products, and you can read the features of those products and then write on them. Moreover, there are several products which you may have been using, and you can write your own experiences on that. There are several websites for which you can write reviews, and they make payments in return. And the best part is, you can register on these websites for free. If you are not that good at writing, but are good at speaking, you can speak about the products through a video, and upload them to some of these websites. Other than that, there are several websites which require online surveys to be done for them, and you can be a part of these, and get paid well.
If you are good at computer programs or have some other skill set, then why not think of using them? There are several people around the world who post projects on websites, and you can bid for such online jobs. Once you complete them, you are paid the bid amount. There are some websites which charge a particular amount for using their services, so make your decisions accordingly.
Telemarketing and Customer Service
There are companies which need online marketing services for promoting their products. For such jobs, you need an Internet connection, so as to make and receive calls from customers and troubleshoot their problems. This can be one of the best ways of making money, especially if you don’t have any particular skills.
Sell an eBook
Writing an eBook and marketing it through the Internet can be one of the best ways of earning money online. If you don’t like the idea of writing, you can buy eBooks from people, and sell them through your website. Once an eBook has been published, you can have a continuous stream of income for a long time to come. For example, if you know the intricacies involved with a particular sports, so you can write an eBook on that and sell it, which would give you additional income for a long time to come.
Sell Stuff Online
There are several websites which provide online auction facilities, wherein, you can sell old things that you have but don’t need anymore. There may be some charges which you need to pay, but you can easily recover that from your selling price.
If you love teaching, then you can think of becoming a teacher. Today, there are several schools and colleges which provide online college degrees, and they need online instructors. You can apply for such jobs. Moreover, there are several other online education programs which you can go for as well. To get an online instructor’s job, you need to hold a Master’s degree in a particular field of study, and have a few years of teaching experience.
Start a Blog
If you are knowledgeable in a particular field, and writing interests you, then you can start a blog of your own. The aim should be to provide useful information to your readers, who would then keep coming back to your blog for more. Once you have a decent amount of traffic on your blog, you can put up ads and start getting a steady inflow of money.
The idea should be to search for a job that interests you. Once you settle down doing it, things will get smooth and you will have a steady income.
If your computer is running slow, you may be wondering if some virus has affected your system, or if your system is slowed down by the antivirus software that has been loaded. Well, you are on the right track. However, these may not be the only reasons why your computer has become slow. There may be other reasons which may be causing this problem. Let us take a look at some of these possible problems.
Why is My Computer Slow to Start Up
It often happens that you have a computer with the best of the configuration, a high memory RAM, a good amount of hard disk space and of course a very good high-speed processor, and yet your computer is slow to start up. The reason for this is that there are a good number of start up processes that you have initiated. Many times, when we install a software, we forget to uncheck the option to start the software during start up. Too many software running in the computer during start-up, may make the computer slow to start up. So, the way out of this problem, is to disable the functionality to start these software during start up. You can also browse the computer’s start up services and disable all such services that have been programmed to start up when your computer boots up. Similarly, if there are any services that keep running in the background, you need to shut down those applications. These applications that run in the background, not only cause other processes that you are running to slow down, but may also make the computer slow to shut down. You can simply go into the ‘Task Manager’ of your computer, if you are using the Windows operating system, by hitting the Ctrl-Alt-Del keys together and end all the unnecessary applications that are running. However, reducing the number of start-up services in your computer, is a better way to counter this problem, because, disabling the applications individually, will not stop them from booting up during start-up.
Basic Causes for Slow Computer
Now, let us take a look at the basic reasons which may cause the computer to run slow.
This is one of the basic reasons that may cause the computer to run slow. If you are using a software which takes up a good amount of RAM, then obviously, the other applications will run slow. Another important aspect that you need to take care of is ‘paging’. When the RAM in your computer is full, the computer processor utilizes some space from your secondary storage device that is your hard disk to run the applications. Hence, it becomes very necessary that you provide some amount of free space in your RAM.
This is what is considered the basic reason, why a computer is slow, and often, the conclusion is right. Adware, malware and spyware software can considerably reduce the computer performance. Of course the easy way out of this problem is to install an antivirus software in your computer. But one thing that you need to keep in mind is that, antivirus software though a necessity, can also reduce the performance of your computer. Hence, it becomes very important that you choose an antivirus software, which does not occupy a lot of RAM.
This is one tip that I can provide you with. Defragment your computer at least once in a month or fifteen days. This reduces the clustering of files in the computer. To do so you just need to click the Start menu, go to programs, accessories, then to the system tools options and select the option for defragmentation. Also remember to delete temporary Internet files from your computer.
For convenience, let us assume that everyone uses Windows. The Windows registry is like the DNA of the Windows operating system and stores all vital information about your system that includes: interface settings, installed programs and program settings, settings for drivers and hardware and personal user profile. This implies that if registry crashes or gets corrupted the entire system will stop working. When you install new drivers or devices, add and remove programs, open and close applications and change their settings, your registry becomes littered with corrupt entries. Your computer’s performance is seriously hampered and causes system errors, freezes and crashes. To prevent your computer from slowing down, proper maintenance of the registry is vital.
So if you too are wondering why your computer is running so slow, you must have got some idea about how to resolve this problem. Your computer is just a machine and it cannot do anything on its own accord, unless you have prompted it to work in a particular way. Many times, we install software without checking each and every step of the installation process. It is in these stages that we are often asked if we want to install some unwanted software along with the software we are installing or if we want the application to start up every time the computer boots up. So follow the tips I just equipped you with. In most cases, taking simple precautions can ward off complex problems.