The initial beta of the desktop client will let users search e-mail and files from their hard drives, said Jeff Weiner, Yahoo's senior vice president of search and marketplace. But the company plans to soon add the capability to search across its other services such as Yahoo Mail and Yahoo Messenger, he said to eWEEK.com.

Yahoo is licensing technology from startup X1 Technologies Inc., of Pasadena, Calif., for its desktop-search client, which will bring advanced query and preview features to the beta, Weiner said. The beta version, available for Windows, will be a free download.

The initial version of the client also will tie into Yahoo's Web search but, unlike in Google's desktop search, it will separate local results from Web results. Local results will appear within the client, while Web results will be shown within a user's browser, Weiner said.

Google Desktop Search, which launched in beta in October, combines results from searching the hard-drive and the Web in the popular Google browser-based interface.

"Ultimately, we want to create a seamless search experience regardless of where the data lives," Weiner said.

Details of Yahoo's plans come as all the major Web search engines delve into desktop search. Microsoft Corp.'s MSN division plans to launch an offering later this month, following its purchase earlier this year of startup Lookout Software LLC.

Ask Jeeves Inc. is expected to release a beta of its desktop-search product late on Wednesday and to provide more details about the service. Ask Jeeves also bought a startup, Tukaroo Inc., earlier this year.

Click here to read more about search-engines jumping into desktop search.

So far, Yahoo's clearest departure from the current crop of desktop-search products the plan to tie in its major services, which is likely to start within weeks of the beta release.

Yahoo will first extend desktop search across its a user's online address book and calendar and Yahoo Messenger instant-messaging chats, Weiner said. Following later will be integration with Yahoo Mail, Yahoo Groups and Yahoo Photos so customers can search the e-mail, discussions and digital images they have stored on the Web, he said.

"There's a lot of information that resides beyond the hard drive but on the server side," Weiner said. "This starts to evolve into a dashboard for your digital life. Yahoo's extremely well positioned to deliver that with 160 million registered users and a huge repository of data that has been created on Yahoo."

Besides the connections with Yahoo's network, the desktop-search client will include a feature for narrowing searches according to attributes. Once Yahoo Mail can be searched, for example, users can narrow their searches based on sender, recent e-mails and attached file types, Weiner said.

In the presentation of search results, the client will display results as a user is typing a query and refine them as more characters are entered, he said.

What about desktop search and security? Click here to read more.

Users also will be able to preview files and e-mails from within the client and complete tasks such as responding to a Microsoft Outlook e-mail within the desktop-search application.

Yahoo already is testing a personalized search service called My Yahoo Search, available on its Yahoo Next site, where users can save and share search queries. The company has not said when the service will be generally available.

Weiner made clear that Yahoo's personalized search and desktop search will increasingly work together, though he did not offer details.

"You should see seamless integration of all this over time--personal, desktop and Web--and that will unfold over the next year," Weiner said.