Today's computer hard drives look a lot like the Web: huge, cluttered collections of content that can make it nearly impossible to find a file manually. So it's no surprise that Web-search giants like Google and Yahoo are competing to make the best hard-drive search engine. Attempting to keep up in this race to conquer what's known as "desktop search" is Blinkx of San Francisco. The startup's software turns search on its head: instead of waiting for the user to type keywords in a query box, the software monitors what the user is working on and automatically supplies links to relevant content from the local hard drive and the Web.

The race heated up in October with the release of Google's desktop search engine. Since then, MSN, Ask Jeeves, and Yahoo have come out with competing products. But even last summer, Blinkx had its software ready to download. It has since accumulated a million active users.

Like all desktop search engines, the Blinkx software runs on the user's computer and indexes the contents: word-processing documents, e-mails, and so forth. Once that's done, the software "reads" whatever the user is working on -- basically anything with text -- and matches the pattern of words in that file with those in files stored on the hard drive and on the Internet. A toolbar at the top of every program window lets the user choose which of the files uncovered in this search she'd like to view: documents on the hard drive, news stories, Web pages, even online video clips.

Delivering search results automatically is one thing that distinguishes Blinkx's search tool from that of its competitors. Another is that Blinkx errs on the side of providing too few rather than too many  results, trying not to inundate users with not-so-relevant links, as some keyword-based search engines tend to do. "When you pick only a few keywords to search, you lose lots of detail and context," says Suranga Chandratillake, Blinkx's cofounder and chief technology officer. "We get to keep all that context, and that's why we get such good results." Of course, whether users will agree about the superiority of the results will depend to a great extent on personal taste. Users will notice that for most documents, the Blinkx toolbar will only bring up three or four results -- and sometimes none -- which may disappoint those accustomed to copious hits from traditional search engines. In that case, users have the option of crafting their own queries in a separate query box.

With $10 million in funding from private individuals, Blinkx says it has enough money to last at least though the year without seeking venture capital financing. The company's first goal is to get more users to download its software. One way to do this, says Blinkx CEO Mark Opzoomer, is to partner with companies such as online retailers and publishers; a branded button on the Blinkx toolbar would only return results from the partner company's site. Because downloading the toolbar is free, Blinkx will rely on advertising -- in the form of a separate ad button on the toolbar -- to bring in revenue.

With a million users, Blinkx is off to a good start. But capturing the next million will be tough. Blinkx will have to reach out to the masses, who may be more apt to try new kinds of searches from trusted companies like Google and Yahoo. Attracting advertising may also be difficult. While it's easy for advertisers to link their ads to keyword searches, it may be more difficult to place ads that are relevant to the contents of personal files, says David Burns, CEO of a competing desktop search company called Copernic of Sainte-Foy, Quebec.

Perhaps the biggest worry is Microsoft. Long before Blinkx came along, the software giant talked about automatic searching based on what a user is working on, a concept it calls "implicit query." Microsoft   researchers have demonstrated prototype hard-drive search software that incorporates this feature, and it may very well be a part of the next version of Windows. If so, Blinkx -- which beat Microsoft to market with implicit query -- could end up being overtaken by the behemoth.