Microsoft release its Live OneCare service today, providing an all-in-one antivirus\/antispyware\/firewall\/backup tool that will cost you $49.95 a year. Microsoft's in a good position to succeed with this: Who better to plug the holes in your operating system than the company that left them open in the first place? (Back in the day, Borland execs used to complain that Microsoft Office developers got early access to new Windows versions. I wonder if the OneCare crew will get to peek at the "known bugs" list before Windows Vista ships?)But enough kidding. Microsoft is apparently serious about this, and the other desktop security vendors need to be nervous. I buy second-party parts for my cars, but only when those parts are significantly cheaper, of equal or higher quality, or offer extra features than ones from the manufacturer. At $50 a year to cover three PCs, Symantec and McAfee would have to practically give away their products to beat Microsoft's price. Quality? That remains to be seen. I'm fairly picky about my security tools; I want them to do the job but not get in my way. That means giving me access to detailed configuration settings so I can make sure things like my network print and storage servers are available rather than causing an overly paranoid firewall to throw off endless "intruder alert" warnings. And these tools can't chew up undue amounts of memory and CPU time. I'll have a better idea about how OneCare fares on those fronts after I get through my 90-day trial.As for extra features, I'm not sure what else anyone could offer me in a security package. The OneCare set looks pretty complete.So this is Microsoft's game to lose. If they don't screw something up badly, they should be able to grab significant market share fairly quickly (and this is without bundling OneCare with Windows, which would surely set off a round of fresh antitrust suits.)\u00a0When I first got into tech reporting, there was a running joke about how you knew a desktop software company was in trouble. The short version: Vendor A stops by to show off the latest release of some product against which Microsoft had just decided to compete. When asked about the new competition, the vendor would invariably respond "Microsoft is just validating our market."\u00a0 Note to investors: The second a CEO utters that phrase, sell, sell, sell.