It's a jungle out there. Here's how to shield your PC.

Protecting computers from viruses is just as important as locking doors and turning on your burglar alarm. If you and your family use e-mail, share files, and surf the Internet, then you are engaging in activities that can allow viruses to enter your computer and spread to others. Since dangerous viruses, worms, Trojan horses, and malicious computer code can wreak havoc, it is essential that you develop an anti-virus strategy.

Computer viruses are parasitic programs that surreptitiously enter your system through infected programs or data files, and then, in some way alter a computer's operation. At the least, they're mild annoyances that attach themselves to files and reproduce, gradually slowing a computer's performance. Some display annoying or obscene messages when they activate.

At their worst, viruses can cause computers to stop working by disabling their ability to boot, or make applications crash, or even obliterate data and wreak havoc on a hard drive. If you're unlucky enough to contract an aggressive virus, you're likely to find that it has run rampant, infecting many of your files, as well as your hard drives and disks.

Like their biological brethren and namesakes that spread from person to person, computer viruses spread from computer to computer by latching onto computer files and modifying their codes. When you run an infected program, open an infected data file, or launch an infected e-mail attachment, the virus loads itself into your system's memory where it looks for other programs and files to latch onto. Thus, if someone gives you an infected file, it can introduce a virus onto your system. And if you then give another friend a different file from your computer, the virus infects that system, and so on.

Anti-virus programs such as Norton Anti-virus or those from McAfee work for you in several ways. First and foremost, these programs identify and find viruses by their signatures-combinations of bytes unique to a virus' own distorted ways-that reside in memory or on hard drives. An anti-virus program scans a system's memory and drives, and looks for these signatures that indicate a virus. And when they find one, they alert you, and then remove it.

Sometimes, these programs are successful at removing a virus, and can give you back your files intact. Other times, they will tell you to delete the infected file to remove the virus from your system. (That's why it's always important to back up your data. You do have backups, right?).

Any time someone sends you a new file or disk, an anti-virus program can scan the file or disk to be fairly sure that there is no for known viruses on it. Keep in mind, though, that macro and program viruses only activate themselves as you open or activate the infected files. Thus, viruses can reside on your hard drive in contaminated data or program files, as unopened e-mail attachments, or compressed Zip files, and never rear their ugly heads. When you scan your drive, the antivirus programs can find them before they have a chance to cause damage.

To scan for viruses, a program has to know what it is looking for in order to recognize them. And because there are new viruses constantly hitting the streets, anti-virus programs have to be frequently updated with new signature files so they can identify the newest crop. Scanning with an out-of-date signature file is like tracking a criminal with the wrong fingerprints. To stay up to date, all anti-virus programs let you regularly update the software with new signature files across Internet connections. All you have to do is click a button while connected to the Internet, and these programs perform the update for you.

Areas to consider when purchasing anti-virus software include the features provided by each product and their relative ease of use. You'll also want to understand how difficult it is to upgrade virus definitions, how long you can obtain free signature updates, and how much subscriptions cost. Paying for anti-virus protection isn't fun, but neither is an infected computer. It's simply a fact or modern computing life.

Related Story: Norton Internet Security 2003 Professional Edition

1/31/03 www.daytrum.com Editorial Staff

Protect Your PC From Viruses