It's no secret that viruses are big business these days, but yesterday, we got some clues as to just how big. Microsoft (NASDAQ:MSFT) said that it plans antivirus software, a prospect that sent shares of Symantec (NASDAQ:SYMC) tumbling. As far as Symantec goes, the prognosis could be worse, but it underlines the significance of viruses to business.

Meanwhile, Motley Fool Stock Advisor pick Dell (NASDAQ:DELL) is joining the fight, too. If you were wondering how it might affect a maker of hardware like Dell, a USA Today article outlined why it's in Dell's best interest to go on virus detail.

Consumers with sick machines inundate the Dell support lines; 20% of all regular calls are of that nature, with the calls spiking 200% to 300% when a high-profile virus strikes. So while a virus is not a hardware problem, it becomes one when a consumer doesn't know his or her machine's infected and just needs to make it work.

Dell plans to offer education for customers and will work with antivirus software makers in lowering prices for the software bundled on its machines, as price is likely a significant barrier to adoption for some computer users.

Symantec may be deeply entrenched in the antivirus market with its Norton Antivirus software, but the panic associated with the entry of Microsoft into the market is understandable. Microsoft's high profile and deep pockets certainly make it a force to reckon with.

However, Symantec investors should take some comfort in knowing that Microsoft may have learned something from past antitrust problems when it embedded software into its operating system. Microsoft said its AV software will be available on a stand-alone basis, giving rivals a fighting chance.

Although Microsoft has the big pocketbook and a very vested interest in improved security, Symantec and its rival Network Associates (NYSE:NET) have expertise and focus in the area. Plus, Microsoft's reputation has been more for swooping in and throwing its weight around than innovation, and it's going to have its work cut out for it, especially given past criticism that it's a little slow on the draw.

After all, the loonies and brats (likely also basement dwellers) that write viruses move fast, and they love to get under Microsoft's skin in particular. Further, the virus environment keeps evolving. Earlier this year, one took a disturbing turn, and just yesterday, there was word of the first-ever mobile phone virus, which is not damaging but disturbing nonetheless. Companies involved in all aspects of technology need to focus on keeping it clean, or run the risk of losing both customers and efficiency, which damages their top and bottom lines.

Dell is a longtime Motley Fool Stock Advisor pick. What else makes the grade? Try a subscription for six months, risk-free. Or talk about the things that make computers sick on our Viruses, hoaxes & spam, oh my! discussion board.

Alyce Lomax does not own shares of any of the companies mentioned. She runs antivirus software on her Apple (NASDAQ:AAPL) iMac, but has never had any problems with viruses on her machine.