Your home computer is a popular target for intruders. Why? Because intruders want what you've stored there. They look for credit card numbers, bank account information, and anything else they can find. By stealing that information, intruders can use your money to buy themselves goods and services.

But it's not just money-related information they're after. Intruders also want your computer's resources, meaning your hard disk space, your fast processor, and your Internet connection. They use these resources to attack other computers on the internet, hack other people, and send millions of pieces of unsolicited e-mails, also known as spam. In fact, the more computers an intruder uses, the harder it is for law enforcement to figure out where the attack is really coming from. If intruders can't be found, they can't be stopped, and they can't be prosecuted.

Why are intruders paying attention to home computers? Home computers are typically not very secure and are easy to break into. When combined with high-speed Internet connections that are always turned on, intruders can quickly find and then attack home computers. While intruders also attack home computers connected to the Internet through dial-in connections, high-speed connections (cable modems and DSL modems) are a favorite target.

How do intruders break into your computer? In some cases, they send you e-mail with a virus. Reading that e-mail activates the virus, creating an opening that intruders use to enter or access your computer. In other cases, they take advantage of a flaw or weakness in one of your computer's programs - a vulnerability - to gain access, using port scans and other probing programs.

Probably one of the most common ways is through file sharing. Downloading of music, movies and software over the internet is a dangerous activity. In most cases you have no clue where you are getting files from. Was this person on the other end a hacker putting out a virus or trojan, or a person who's computer is so infected with worms and virus' that most files are now infected, including the one you just downloaded.

Once they're on your computer, they often install new programs that let them continue to use your computer - even after you plug the holes they used to get onto your computer in the first place. These backdoors are usually cleverly disguised so that they blend in with the other programs running on your computer. While you my have a firewall and anti-virus program installed, once the intruder gets into your system, there is a good chance your protection is no longer functioning correctly.

Many worms, trojans, and virus' have built in lists of program files (sometimes hundreds of files) to look for, delete, or modify so they no longer protect your system properly. In many cases you can go and install a new anti-virus, firewall, trojan scanner, or other security product and not correct the issue. Yes, you may find some of the things that have been installed on your system, but in most cases not everything. Most intruders once in your system will install their own software or modified software that doesn't match things your anti-virus or other security software may be looking for.

Because of the issues listed above the quickest and safest way to clean your system is to format the computer. This process will remove any software installed by a worm, virus, or hacker. If there is information you cannot afford to lose, make a backup onto a disk. Do not load this back onto your system until you follow the steps listed in "Now that I have reformatted, how do I stay safe?".

A format should be done by a computer professional due to the sometimes tricky reinstallation of the operating system, drivers, and other programs needed to function on the internet properly. Some computers may come with a System Restore disk, this disk may or may-not format the computer. Some system restore cd's only reinstall certain programs, or reload a backup of your computer's files, thus still leaving the trojan, worm, or virus. It is best to call your computer vendor if you have one of these disks, and inform them you have been infected or hacked and need to format your computer.

Once your system has been reformatted you should install an anti-virus program, firewall, and other misc security software. If you made backups of files you couldn't afford to lose, do not load these file back unless you must have them back on the computer. These files may contain the original cause of the infection, or the backdoor the intruder used to get in. If you need there backup files loaded, you should first scan them with your anti-virus program and other security tools you may be using. Make sure to keep your security programs up to date, and out of date program will not protect you from the new threats that come out daily.

Once you are back online always use caution when reading e-mails, downloading files, or even chatting online. Make sure you do not open e-mail from people you do not know, and if it is someone you do know, send an e-mail to them to ask them if they just sent you an e-mail. If your friend of someone they know is infected it may be the infection sending you e-mails from their computer trying to infect you.

When downloading files to your computer, always scan the files with your anti-virus and other security tools you may have. This is a very important step because when you download you are bypassing the security of you computer and bringing the files directly into your now clean system. This process of scanning your downloaded file is a very quick process and should take only a couple seconds since the anti-virus is only checking a couple files as compared to the whole computer.

Finally with chatting never run a program or file sent to you in a link. The person on the other end of that chat may not be who you think it is and you might be opening yourself up to being infected again. If you ever do accept a file or program from someone you are chatting with, make sure to scan that program or file just like you would with regular downloading. Following these steps should keep your system clean, running smooth, and keep you and your information safe.