Computer viruses have been around in one form or another since the early 80s. The earliest viruses were transmitted between computers via floppy disk or on school networks. With the advent of the Internet, viruses became a major problem. At first, you needed to get an infected email attachment and run it to get infected. Nowadays, thanks to Microsoft's HTML email program, Outlook Express, you can get a virus just by viewing an email. The viruses can come from bad ActiveX scripts in the email.

Microsoft included a basic antivirus program called Microsoft Antivirus in its Windows 3.1 operating environment. The dumb thing is, they didn't include it in Win95, which was their first Windows to be able to use the Internet. Duh, Microsoft.

As the years rolled by, viruses got nastier and nastier. Thanks to ActiveX and Java applets, you can get a virus just by going to a bad webpage. You can also sometimes get viruses by downloading a trojan, which is a program that masquerades as a harmless program, such as a game, but is a virus in truth.

The newest and most terrifying kind of virus is the worm. Worms don't need to arrive in email, or even be downloaded from webpages. Worms can infect Windows NT, 2K and XP machines as soon as they come online. The first such worm was Blaster, which wreaked havoc with WinXP machines last summer. It would cause them to spontaneously reboot.

This past spring, a new worm reared its ugly head. This was called Sasser. It exploited a weakness in the program LSASS.EXE, which is a file WinXP needs to use the Internet. Like its predecessor, it would cause the machine to reboot spontaneously. There would be an error saying that LSASS.EXE had crashed. About a minute later, a dialogue box would pop up and say that Windows would be shut down in one minute, and would give a countdown.

Sasser is easy enough to thwart. Go to Start Menu>Run>Command>type shutdown.exe -a and hit Enter. This aborts the shutdown. It's very important to patch Windows against these worms, if you haven't already done so. Go to Windows Update and download the security patches.

Once patches have been applied, you should also have an antivirus program and keep it updated.

AVG Antivirus FREEWARE
Avast Antivirus FREEWARE
eTrust EZ-Antivirus SHAREWARE
Panda Antivirus SHAREWARE