By Steven Presar

You know basics of computer virus protection -- don't open email attachments' from senders that you do not know. If you follow this simple rule, your computer will be safer than most.

But a few weeks ago, a computer worm called “sasser”, caused havoc with Microsoft Windows computers throughout world.

This sasser worm spread in a completely different way, not bothering with email (the way most viruses spread) but instead exploited a security hole in Microsoft Windows.

This security hole allowed any computer connected to internet to be infected. The worm spread and infected computers almost invisibly, thus many people were caught by surprise when their computer problems began.

A computer virus is a set of computer program instructions that attaches itself to programs in other computers. Viruses are often parts of documents that are transmitted as attachments to e-mail messages. A worm is similar to a virus but is a self-contained program that transports itself from one computer to another through networks.

The most obvious symptom of sasser worm was that infected computer would automatically shut down – thus making troubleshooting this worm a challenge to those infected.

A Plan of Action for Small Business

One of ways to prevent your computer from becoming infected by a virus or worm like sasser would be by installing a “firewall” on your computer system.

Any computer connected to Internet, is vulnerable to electronic worm or virus attacks. You are protecting your computer system by setting a firewall between your computer or networked computers (LAN) and Internet.

A firewall examines, filters, and reports on appropriateness of all information that passes through your computer network. A firewall may ensure that information received from an outside source is as expected and does not contain computer a virus or worm.

This protective barrier between your computer and Internet will monitor incoming and outgoing internet traffic and warned you of virus or worm before your computers became infected.

Microsoft Windows XP includes a firewall, but it may not be enabled on your machine because Microsoft turns it off by default.

If you have Microsoft Windows XP and would like to activate your software firewall, follow these steps:

~ Within Microsoft Windows XP ~ Click on Start button and then choose Control Panel ~ Click Network and Internet Connections category (If you do not see Network and Internet Connections category, click Switch to Category View under Control Panel on left side of Control Panel window.) ~ Choose Network Connections. ~ Right-click Dial-up, LAN or High-Speed Internet connection(s) that you use to connect to Internet ~ Click Properties from menu ~ On Advanced tab, under Internet Connection Firewall, select "Protect my computer and network" ~ Then click OK.

You have now enabled your Windows XP firewall.