Microsoft is opening its latest search technology beta Thursday, a spokesperson told internetnews.com. The move represents the latest beta release of the company's search effort, which MSN released earlier this year.

It also represents Microsoft's response to the growth and competitive threat from search king Google. Microsoft has warned that it's preparing a Google killer in the form of a better search tool. But even before Microsoft lets the world in on its latest search beta, Google has already struck at the heart of Windows with a beta release tool to search PC desktops.

Google Desktop Search, which for now works with Windows XP, Windows 2000 Service Pack 3 and above, represents a new front in Microsoft's war for the Web -- and whether it can extend the dominance of its operating system to the Web, this time with search rather than a browser.

Company officials, such as Bill Gates and CEO Steve Ballmer, have promised investors and customers that the company's MSN division will take search capabilities farther than what is currently on the market.

That theme was echoed in late July at the company's financial analyst meeting when Yusuf Mehdi, vice president of Microsoft's MSN division, told the group: "We now have the ability to search beyond what's on the Web today, including data you can't find in intranets, as well as on the Internet, such as deep Web databases."

Microsoft officials have been briefing analysts and select media about the latest beta over the past two weeks, including demonstrations from the MSN division that include search capability of both the Web and a PC, that plucks relevant files including e-mails, PowerPoint files, Excel spreadsheets, contact information and more Web links -- within seconds of a query.

Officials have given no ship date for the new search tool, other than it is expected in the fourth quarter.

In addition, MSNbot, Microsoft's Web-spidering content bot, has indexed well over a billion pages as part of the group's effort to ramp up search in the division. The customized search-driven news service is a beta with media partner MSNBC. The company has also announced plans for blog search, called BlogBot, and a natural language search engine, called AnswerBot.

But search is just one part of MSN's three-pronged growth strategy built on communications services, search and an advertising platform. Another new technology the group is testing is called orchestrated advertising, which Mehdi said would provide a next-generation media experience on the Web, one that would help publishers target more effectively -- and decrease the amount of advertising on a Web page.

"Think of this in the same way that people put signs in the layout of a grocery store," he said. "When you walk in, you see what's promoted at checkout, in the aisles. Orchestrated advertising is the same kind of concept, using the concept of rich media and personalization. The banners are also targeted, or orchestrated, so that a user can interact with the Web ad by expanding its size, replaying the format." After the user closes out of the advertising, or is done interacting with it, a banner ad is replaced by local content.

Susan Kuchinskas contributed to this story