The free download, to be announced Wednesday and released in test form later this summer, also is designed to help manage information overload.

It will be called Windows Live Search, said Kirk Koenigsbauer, a general manager in Microsoft's information worker division. That's the same name of Microsoft's new Internet-only search product, also in test form, but Koenigsbauer said there are no plans to combine the two.

This product will be an add-on to Microsoft's current product for scouring the PC desktop, available now as a free download and slated to be included in Windows Vista. The ability to search corporate networks will be available only to those who use Microsoft's SharePoint server software, which is designed to help companies find and share information.

For about a year, Google has offered a similar free download, which can be used with Google's own search technology for businesses, as well as those from a few other companies. Matthew Glotzbach, head of products for Google enterprise, said he had expected Microsoft to follow with its own offering.

Microsoft also plans to announce Wednesday that it will offer a scaled-down version of SharePoint for corporate search. It will be available this fall, when Microsoft releases a slew of new Office products and server software to businesses. Consumer versions of Office and Windows are due out early next year.

The announcements will come during Microsoft's 10th CEO Summit, an annual gathering of corporate leaders at Microsoft's Redmond campus. This year, the networking event will include bigwigs from Motorola Inc. and Anheuser-Busch Cos. Inc., among others.