Do you have a PC-personal computer at home?(or as some would like to call it, a desktop Pc)

Then you should definitely have come across the term 'Virus'.They are the dreaded things that makes us conscious every time we plug in a memory device, whenever we download a software and even when browsing.They are an integral part of computer these days.There were days when people didn't know what an anti-virus software was.But now as a novice, he/she will tell you at least 3 names of different anti-virus software.

What's more these days it's mandatory for a company to install an anti virus software while packaging a Laptop or PC.Apart from hardware,software and virus problems, there are also adware, spyware, and other "wares"problems too!.You get annoying softwares installed automatically, you get files that suddenly start to vanish, you see that one of your partition is suddenly low on space, and there are thousands of such miseries that these viruses and 'wares' cause.This article will help you understand them better and do the necessary to protect your computer from threats from these pieces of software that harm your computer.

These day's personal computer or computer in general has become an integral part of our lives,at home, at work at banks,etc., computers have taken over the world.So has the problems that arise along with it.One of the main problem are due to the virus or other malicious 'wares'.We store passwords, e-mail IDs ,bank accounts, personal diaries and notes, business plans (in worst case-tender bids!), confidential documents, and much more. There are other risks too, especially when you are online, you are prone to be affected by viruses and spyware. Though viruses and spyware are talked about in the same breath, there is one fundamental difference: a virus is written to cause damage to your operating system, programs or files, usually with no direct benefit to the virus creator. Spyware, on the other hand, is written for gain.

This could be by tracking the surfing habits of a user on an infected computer and sending this information to someone who would send the user advertisements supposedly targeted at him based on his surfing habits.Very strictly speaking, spyware is not intended to cause damage, at least in the traditional sense, but more often than not,they end up doing so on your PC, which is rendered difficult to repair.On the contrary, adware can bring down your PC, a virus can mass-mail annoying contents to all the contacts in your address book, a keylogger can send every keystroke of yours to someone on the Net—and these are just a few risks that are out there affecting PCs. Also, for someone even moderately well versed with operating systems, getting into a poorly-secured PC is child’s play.

So what is computer security?

Computer security, is the ways in which you can prevent people from accessing data on your computer, keep your computer safe from viruses and spyware, and protect yourself from hacking and phishing. Also securing your personal files are indeed important (even if I don't emphasise on it).

What are the common sources of virus or the other troublesome 'wares'?

There are a variety of sources, ranging from e-mails to games.Yes you read it right-games.Some virus piggyback on executable files like games and when you double click the game, to play, the virus gets activated.There are also other sources like an external memory device-it can be a pen drive(or a thumb drive-flash drive-data drive-or whatever you call it).The viruses can copy themselves and a file(usually an INI file, that makes the virus autorun) to the root directory of the pen drive and execute when the pendrive is active.

The next important source to consider is virus or malicious programs being copied onto your computer- you might have copied some files and unknowingly you might have copied viruses along too, so when you paste the files in your computer, the viruses may get active.The more regular source of virus is internet.All sorts of viruses originate from the internet.A file is shared, along with a virus in it- if it is a great game or a software, in no time, there will be millions of copies of the files in the internet.Also some sites, when visited can download some adwares or malwares to your computer.That is why internet security and website certification has been included in antivirus softwares these days.

There is one initial thing that you must do, until your computer is accessed by many unknown users(like in a internet cafe or a studio).make sure you have an unique password to the admin account.Most people do not recogonise the importance of keeping a password for the admin account.It some one finds your computer off guard, one can easily get access to all information through the administrator account.The next thing you need to do is deny any access to your computer even restricted access, we are talking about the default guest user account.Every windows xp has one such account.Make sure that you turn off or disable the Guest Account.Also Delete / Disable Unused User Accounts.These are the most basic security measure that anyone must do.

There are many ways that we can assume that your computer is infected with viruses.But most sceptical people suspect of an virus infection as soon as they see that it takes 20 seconds to copy a file and not 15 seconds! so the first advice is don't be pessimist.There are several cues that you can observe before coming to the conclusiopn that your Pc is infact infected by virus, let's see some of them.

You have an active antivirus software, everything seems fine, but suddenly one day you switch on your Pc and the Pc restarts on it's own!.If youknow how to get to the safe mode, try it and try to rectify the problem by running virus scans and system error checking.If you can't then it might be a virus(there is also an option for corrupted Operating system files, so don't forget to consider that too!)

There is one serious indication of virus infection-if the anti-virus is disabled and you didn’t disable it, you’re very likely infected. There is nothing to panic, first try reinstalling the antivirus. If that doesn’t work, then panic!.There is also another closely related signs of infection- you are able to install a mario game or a simple paint program into your computer, but you can't get an anti virus software installed, then you must panic again!.

This cue is kind of more unusual.Some claim that unable to print properly can be signs of virus infection in your Pc.But hey!, it can also be due to the reason that you forgot to replace your cartridge!.

Many programs in your computer seems to be acting strangely.It can be a game you installed lately, or any small utility software you installed, that opens and closes in a flash when you double click it.Or some applications seem to be executing(you get the hourglass cursor) but it never starts and sometimes makes the computer to freeze.Then you can be sure there is virus in the computer.

Your drives have wired icon instead of the standard icons or sometimes when you try to get into a drive, the drive opens in a new window.Or even worse, sometimes you can't even access a drive even though it is visible in my computer-Then there is a virus hiding in the root directory of your drives.

If you just installed a program successfully and it doesn’t work properly, or if its icons have vanished, don’t reinstall it! There’s no time to waste quickly do a scan.

Your computer might stop responding often.This is more so a sign of an infection with Windows XP.you are working on a software or just watching movie and suddenly your computer goes into a freeze.Also sometimes you get your desktop, but you can't move the cursor or click on an icon.This means that some program is using all the resources offered by the CPU, then it's definitely got to be a virus.

Unexpected error messages with weird codes! Of course, error messages are seldom user-friendly, so the key here is how often they pop up, and how weird they are.For example, a big red cross and an OK button that doesn’t say “OK”.Sometimes you get a 'Don't send' error message often or your desktop suddenly vanishes and reappears within seconds- it means that the explorer is restarting for some reason( which it doesn't do normally).

If despite all warnings about viruses through internet and e-mails, you still opened a suspicious-looking attachment and immediately after that, everything (or at least some things) went funny, then hit Scan. And hope that the anti-virus will scan and find the virus that you let in to your Pc.

This might have occured to many of you - someone tells you he or she got an infected file from you when they copied some files from your computer to their computer.Then you almost certainly have something bad on your computer. It might or might not be a virus, it's upto your antivirus software to detect it.

You wake up one fine morning and get your computer started to check e-mails and you find funny icons that you've never seen before!, then you are not dreaming, your computer is infected!.

Types of threat include - worms,virus,trojan,adware,spyware( genrally malwares).[ these are the main villians there are others too]

Malware, is short for malicious software.These are softwares that enter the Pc, without your permission and are capable of damaging the files on the system.This is a general term used by computer professionals to mean a variety of bad,intrusive, or annoying software or program code.But most of you must have heard the word 'computer virus' rather than the term Malware. Malware includes computer viruses, worms, trojan horses,spyware,adware, and other unwanted software.

Have you seen worms that eat leaves of a plant within days? Computer worms are something similar-they don't actually destroy though.But computer worms are malicious software applications designed to spread via computer networks. Computer worms are one form of malware along with viruses and trojans. A person typically installs worms by inadvertently opening an email attachment or message that contains executable scripts.Once installed on a computer, worms spontaneously generate additional email messages contaning copies of the worm. They may also open TCP ports to create security holes in the network,for other applications, and they may attempt to flood the locan area network-with which youshare resources in a network, with a command of Denial of Service to data transmissions.

Viruses are sometimes confused with computer worms and Trojans, which are technically  different. A worm can exploit security vulnerabilities to spread itself to other computers without needing to be transferred , and a Trojan horse is a program that appears harmless but has a hidden purpose to itself. Worms and Trojans, like  viruses, may cause harm to either a computer system files and data or the performance, or networking capacity, when they are executed. Some viruses and other malware have symptoms noticeable to the computer user, but many are almost invisible.

We can rather say that computer virus is a computer program that can copy itself and infect a computer.A true virus can only spread from one computer to another (in some form of executable code).For instance because a user sent it along with other files accidently over a network or the Internet, or carried it with the files on a removable medium such as a floppy disk(out dated!), CD, DVD, or USB drive. The main cause for virus infiltration may be because it has been copied via a network or the system has unrestricted assecc to many users.Either way it's a problem.Hence like the real life counterpart, the viruses need hosts to survive-Give them no way to spread themselves, then you can stop them.

There are many types of viruses, we've some funny names for viruses too(fun love, rain drop, redlof,etc.,) but the main categorisation of viruses are as follows:

You must have seen the film Troy! no?.Well then you need to get the explanation about troy and trojans.Trojan got its name after ancient Trojans.During a seig of Troy, ancient Trojans believed that the large wooden horse left behind by the Greeks outside the gates was a sign thatgreeks wanted peace, since they were weak to go on fighting.The Trojans accepted that gift and brought it inside their city. But it turned ou that the Greek soldiers were inside that horse. During night they opened the main door so that more soldiers could come inside the city and they could easily attack on the Trojans.Similarly a computer Trojan appears something of no importance- it may be an executable file or an VBS coding file or simply an unknown file format.But in reality it harms your system.They are silent killers!.Mostly people confuse the term computer Trojan with computer virus.

They think that both of these are same. No doubt they both infect your computer but they both have slightly different characteristics. Trojan is a unwanted program that cannot replicate itself like the computer virus but can cause serious security problems.It can spread only if copied manually by an user unknowingly.Usually trojans are deployed in a computer,to create a backdoor to your computer which allows the hacker to do anything on your system or we can say that the hacker will get control on your system without your permission. He can see your e-mails, record keystrokes, access password protected accounts and can get any type of information about your computer.It can doannioying functions like rebooting your computer or deleting files.It also sometimes installs spyware which may take you to the unwanted sites.You might have experienced some of these, while working with your computer.

Now we come to Adwares- we have adware and spyware blockers, but what are they in the first place?'adware' is an abbreviation for advertising-supported software. Adware comes bundled with some commercial software which, upon installation, installs packages that download advertising material to your computer and display them.These ads are usually displayed when the user is using the original software application.

But, this is not always the case.Sometimes they act on their own and keep popping advertisements when you are not accessing the main application.Most of you who have installed a lot of softwares would've experienced adwares.Sometimes, halfway through the setup, the setup dialog box displays asking whether you need some toolbar installed or another utility installed along with the main software you are installing.But don't confuse adwarewith supporting softwares.Sometimes a setup might need to install supporting softwares(like runtime environments,plugins,etc) to run properly.

We've seen that adware is usually bundled with a commercial software. It can install itself on your computer either with your permission or without your knowledge when you install the software package. Some forms of adware are also present in the form of pop-up banners that pop up when you visit certain sites.These ads, sometimes referred to as “Java traps,” open up in several mini-windows—each time a window is closed by the user,code that spawns another window is activated.It collects information about how one is using one’s computer and the content transmitted therein, and based on this, displays “relevant” ads in your browser.Sometimes, when you login or click a button or link, new pages of ads get opened.Programmers sometimes add adware to their software packages in order to recover some of the cost of developing the package.

If the package is freeware, then the adware is used to make up for the entire cost of development. Shareware packages also sometimes carry adware that is activated once the trial period is over.You seem to get those annoying dialog boxes everytinme youlogin, saying the trial period has expired, even worse some pop-up between intervals to remind you to register or checkout a website.Some P2P clients, such as KaZaA, have adware ( Gator, TopSearch, etc.) that install on your computer. However, there are very few examples of such “good” adware.Good adware allows you to uninstall it whenever you like.Adwares can have a lot of negative effects on your computer.Working invisibly either in the system tray or as a background service, adwares can take up some space in your RAM.It can also slow down your Internet connection, as a lot of bandwidth can be used to download ad content.

Spyware, as the name sounds- spies on your computer.It may be recording your internet activities or monitoring the webpages you visit or even record keystrokes thus getting to know your personal IDs and passwords , even worse they can record your credit card or account number and send it to a third party through internet or a network.It is intentionally designed to

stealthily install itself and monitor the user’s activity, accessing information that can easily be used to someone’s profit.

IN simple words, sypwares are designed to gather information about a computer user without that user’s permission and knowledge. Some spywares, as said before, can track your internet usages, send it to any online advertising company and the advertising company will annoy youwith ad mails.Yet other versions of spyware can take more personal information from your Internet history such as credit card numbers and passwords.Spyware is usually developed by individuals who want to infiltrate computers and use it to their profit, and if they are stealing sensitive data, you can be sure that it's someone you know, worse- it's someone near to you!.

Spyware, once installed on your computer can affect the performance,since it consumes a large amount of RAM.Spyware has prevailed not only in sites with not only explicit content, but also to sites with other accessible Web content like downloads from sources that aren’t certified. You might think it is cool to download the latest release of a software from any warez site, but think again.many links contain softwares bundled along with spywares.When unsuspecting user, installs or uses a patch, the spyware is automatically launched.The same goes for some P2P clients (like Kazaa, Morpheus,Ares etc.,).

Remember a popup in your internet explorer, that says activex content is blocked? well some online programs need activex controls to access the resources of your computer like online scanning or downloading a software or installing directly from internet.Spyware programs are getting more notorious everyday. They could install a variety of application DLLs on your computer that allow hackers to get a hold of your computer. These DLLs can do a variety of things to your computer from monitor your keystrokes on or offline to accessing your word processor, hijack your Web browser, display advertisements, and more.

So the next time you download some freeware, think before you click download.Though one cannot be 100 per cent safe, there are some simple rules one can follow while installing freeware, or any software for that matter, to ensure that spyware applications do not install themselves on your computer.Download software only from trusted and reliable sources.If you really want to install a software you downloaded, but are not sure of its integrity, you should ask someone who knows more about the subject. Even a simple Google search should bring up some answers about your doubt.The rule is: only install software the contents of which you’re sure of.Spam is one of the leading sources of spyware. A large amount of spyware (posing as Trojans) is spread through e-mail.Use your discretion and a general sense of caution when clicking on Internet ads .

A lot of banner ads that pop-up, also some ads tempt you to click on them , do so under your own risk.Everyone needs pop-up blockers, and luckily, most new versions of popular browsers have pop-up blockers already inbuilt.It is advisable to install the latest version of your Web browser.Also make sure that you've installed a decent firewall.But you may ask 'isn't there one built into Microsoft windows?' yes but it's like a wall protecting an ocean.Go for firewalls like zonealarm,etc.I recommend using the softpedia.com webiste to locate freeware firewalls.Also try to install a spywaredetector( apart from antivirus) and a disk cleaning software, that is capable of cleaning not only files, but also startup items, registry, unwanted files, etc.,