Microsoft fended off Google's antitrust complaints by agreeing to make it easier for computer users to choose competitors' programs, an increasingly common response from a company long accused of using its operating system's dominance to choke competition.

Microsoft's compromise with the U.S. Justice Department, detailed in a report released late Tuesday, allows Windows Vista users to set a non-Microsoft program as the default search engine on hard drives. Microsoft will also add a link to that alternate program in the Windows Start menu, but will not change the way Vista "Instant Search" technology works.

Recent concessions by Microsoft are part of a broader battle between the two companies. While Windows continues to dominate the desktop operating system market, Google's ability to make money from search advertising has left Microsoft scrambling to catch up. Google has also stepped into traditional Microsoft territory in the past year with a set of free, Web-based programs for word processing, spreadsheets and presentations.

"Windows Security Center (in Vista) was sort of biased toward Microsoft products," Heron said. But after talks with the security community, Heron said Microsoft opened Vista up more to competing software. Microsoft is also expected to release code that restores security programs' access to the Vista kernel.

Tuesday's regularly scheduled status report came after Google filed a 49-page document with the Justice Department in April, claiming that Vista's desktop search tool slowed competing programs, including Google's own free offering. Google also said it's too difficult for users to figure out how to turn off the Microsoft program.

Google's claims were intended to show that the world's largest software maker is not complying with a 2002 settlement in which the government concluded Microsoft used its near-ubiquitous Windows operating system to throttle competition. Microsoft is now bound by a consent decree that requires it to help rivals build software that runs smoothly on Windows.