Viruses are self-replicating programs designed specifically to disrupt the functions of computers and networks. They often but not always spread via e-mail. In the real world, viruses are akin to vandalism. The intention is malicious and destructive.

Spyware has a different intention -- financial gain. Spyware spies on your Internet habits, notices what interests you and attempts to direct you to places to make purchases. It can operate via Trojan Horses, which make back doors into your computer, permitting the installation of alien software. When a computer is infected by a lot of Spyware, all of it competing to gain your attention, it can slow down function to a grinding halt.

Anti-virus programs are targeted at detecting and removing viruses from you computer. Anti-spyware products target spyware. There is some, but only some, overlap between the two.

Try booting your system up in Safe Mode (tap the F8 key as your system is powering up and choose Safe Mode from the menu that appears). Then run a complete system scan with your anti-virus software in Safe Mode. Virus scanners have better luck eliminating viruses in Safe Mode.

If you can get on-line, you can run a powerful free system check at the Trend Anti-Virus site.

Avoid downloading free stuff, no matter how innocent looking -- this includes weather bugs, wall paper, smileys, screen savers, pretty e-mail stationery, tool bars, shopping helpers, sources of coupons, and free music.

Safe and helpful free downloads includes Adobe Reader, the Flash player, Quick Time, Real Player, the Google toolbar, and the anti-virus and anti-spyware programs referenced on this page.

Every Internet connected computer needs active up-to-date anti-virus software. It's essential.

Whole Security Suites, like those published by Norton and McAfee, however, can be so complicated that the cure can become worse than the disease.

We currently (6/06) recommend one of two free antivirus programs: AVG -- currently available at http://free.grisoft.com, and AVAST available at http://www.avast.com. The latter is likely the best, but it does require that you register. Upon registering, you'll receive a product key via e-mail, which is required to enable updates for more than a year.

Any computer with adventuresome Internet users (particularly curious teenagers) also needs an active spyware detection/removal program.

We recommend SpyDoctor, available for $29.95 annually. You can scan your system free, but must pay for a license before the software will actually clean up what it's found.

As of this writing, you can also try Microsoft's new product Defender -- still, as of 6/2006 available free in its beta version.