Google Inc. unveils a computer and Web search tool on Monday using self-updating navigation and personal information software that puts it in more direct competition with Yahoo, Microsoft and AOL.

The creator of the world's most popular Web search system said it was branching out beyond pure search to help users manage e-mail, instant messages, news headlines and music.

Google Desktop 2, as the new search software is known, helps users locate information stored on their own hard disk, on office network drives they may use and on the Web. Details can be found at desktop.google.com.

The heart of the system is a tall, rectangular "sidebar" with a set of panels that provide glimpses into the latest "live" information of interest to the user. It actively learns from each move a user makes to personalize what is featured.

"We really want to have people be able to sit back and watch the Web come to them," Nikhil Bhatla, product manager of the Google Desktop product, said, adding that: "We have tried to provide a lot of information in a small amount of space."

Innovative features include a headline syndication system that adds Really Simple Syndication (RSS) feeds of frequently visited sites, without any special user intervention. Aside from searching the Web, Google will trawl Outlook e-mail and PC program data like Word, Excel, Adobe PDFs and instant messages.

"All this information is available at one glance," Bhatla said. "You don't have to manually do anything," he said. Still, each feature is designed to be easily customized when desired.

SUBTLE PRESSURE

Step back from the screen and increasingly desktop applets, instant messaging windows, mobile phone browsers and interactive TV menus all look alike. Lines are blurring between different ways of navigating computers, phones and television.

Google is moving beyond "Coke Classic" - the basic experience of searching the Web through the browser for which it is known. In ways not always apparent to the user, Google is seeking to control more of a users' computer experience, the way Yahoo, Microsoft and America Online do.

Increasingly for Google, this means that users of its information management tools will not need such tools from Microsoft or Yahoo, and vice versa.

The downside is that Google Desktop's powerful information-vacuuming capabilities can compete for a computer's resources with these rival programs.

"There seems to be parallel development going on among all the major players," said Greg Sterling, a Kelsey Group analyst. The major Web media players all are creating "invisible walled gardens" that are less open than they first appear, he said.

Google's strategy remains focused on search and information management, but in small yet vital ways, users are being nudged to choose sides.

Just last week America Online introduced a new version of its popular AOL Instant Messenger (AIM) that emphasizes e-mail, radio, Internet phone-calling, text messaging with mobile phone users, even Web-based TV.

AIM targets people keen on all the new-fangled Internet communications. Yahoo lures entertainment fans and socializers. Microsoft attracts office workers. Google draws the Web-based information worker, but covets the other audiences too.

Yahoo offers its own "sidebar" within a user's browser, which manages music, photos and instant messenger conversations alongside whatever Web page Yahoo users are viewing. Yahoo recently acquired Konfabultator, which first popularized the modular programs it calls Widgets among Apple Macintosh computer users. Google's sidebar is similar.

In a challenge to Microsoft's dominance of the computer desktop, users of the Google Sidebar are encouraged to bypass the Windows desktop and "start" navigation menu. The Quickfind feature allows one to return to recently used applications or Web sites without extra mouse clicks.