Microsoft will be moving its Web search service – now dubbed Windows Live Search – from beta to final, starting on September 12.

Windows Live Search is the renamed and revamped replacement for MSN Search. Windows Live Search is powering the search on MSN.com, as well as on Windows Live.com – another Live property that Microsoft made available in final form, starting on September 12. Live.com is a customizable home page that users can use for search, as well as to track news, RSS feeds and blogs, images and video.

Microsoft officials also announced on September 11 that Windows Live Local Search, which provides bird's-eye imagery and mobile search, will be moving from beta to final release status in the U.S. and the U.K. on September 12.

Microsoft will stage the migration from beta to final of Windows Live Search between September 12 and September 14, said Derrick Connell, general manager of Microsoft' search business unit. The current plan it to move five percent of its search properties to the final Windows Live Search code on Tuesday; another 25 percent on Wednesday; and the rest on Thursday, he said.

A number of other Microsoft search-specific properties remain in beta, including Windows Live Academic Search, Windows Live Product Search and Windows Live QnA.

Microsoft is in catch-up mode on the Web search front. In July, according to comScore Networks, Google sites were responsible for 43.7 percent of all U.S. online searches. Yahoo sites were responsible for 28.8 and Microsoft sites handled 12.8 percent of all U.S. online searches.

Microsoft officially launched the beta of a number of its search-related properties in the fall of 2005. The company has continued to refresh the beta builds of its search products. Late last week, for example, Microsoft made a number of bug fixes and customization tweaks to the Live.com beta page.

With the final version of Windows Live Search, Microsoft has made improvements to its relevancy-ranking algorithms and its query-refinement capabilities, said International Data Corp. analyst Sue Feldman.

Feldman said she was impressed with the quantity of usability testing that Microsoft has been putting into its search products.

"Google doesn't talk about how they do usability testing," she said.

Microsoft also has made improvements to the image search capability that is part of Windows Live Search, said Microsoft's Connell. He cited among the new innovations the smart scroll, scratch pad and related-people search functionality that is part of the final Live Image Search code.

IDC's Feldman was bullish about the cross-pollination happening between Microsoft's information worker, Live Labs, desktop search and Windows Live Search teams.

"Microsoft may have an edge in understanding" in the search space, Feldman said. "Microsoft has tremendous depth in search resources that many don't realize."

Windows Live is the overarching brand name for a growing family of Web services that Microsoft is testing and delivering to consumers and businesses. At latest count, there are more than 40 properties branded "Windows Live" that are in various phases of rollout. Microsoft is making some of its Windows Live properties available as free, ad-supported services; it is charging for others.

The final versions of Microsoft's Windows Live search properties can be found via Microsoft's Windows Live Ideas page.

(This story was updated on September 11 to include comments from Microsoft's Connell.)