Microsoft will change how desktop search works in its Vista operating system by the end of the year, in response to an antitrust complaint by rival Google, the company said in court documents released late Tuesday.

Microsoft has agreed to make changes that would allow end users and OEMs (original equipment manufacturers) to select a default desktop search program in Vista that's not Windows Instant Search, according to a status report in the ongoing court review of Microsoft's 2002 antitrust settlement with the U.S. Department of Justice. The change will come in Windows Vista Service Pack 1, due out in beta form by the end of 2007.

"Microsoft believes that Google's complaint is without merit," Microsoft's lawyers wrote in the status report, filed with the U.S. District Court for the District of Columbia. "Nevertheless, Microsoft worked with the Plaintiffs in a spirit of cooperation to resolve any issues the complaint may raise."

Google, in a statement, said the search changes are welcome, but more needs to be done.

"Microsoft's current approach to Vista desktop search clearly violates the consent decree and limits consumer choice," David Drummond, Google's senior vice president and chief legal officer, said in the statement. "These remedies are a step in the right direction, but they should be improved further to give consumers greater access to alternate desktop search providers."

Earlier this month, Google confirmed that it had complained to the DOJ about Vista's desktop search functionality. Google had complained that it was difficult to replace Vista's search with products from Google or other competitors.

In the 2002 settlement, Microsoft agreed to allow competing middleware vendors to easily replace Microsoft software with their own in Windows operating systems.

As part of the desktop search agreement, software vendors will be able to register their products as alternatives for the Vista search. The default search selected by the computer user or OEM will launch whenever Vista launches a search result window, and the default search will have space in Vista's start menu.

Microsoft will also tell software vendors and OEMs that the desktop search index in Vista is designed to run in the background and "cede precedence over computing resources to any other software product, including third-party search products," the DOJ said in its portion of the status report. "Microsoft will emphasize that there is no technical reason why OEMs and end users cannot, if they choose to, install additional desktop search products on their systems."

Microsoft will also provide technical information to allow other desktop search providers to design their products to optimize computer resources, the DOJ said.

The plaintiffs in the case, including 17 states that sued Microsoft for antitrust, are "collectively satisfied that this agreement will resolve any issues" in the Google complaint, the DOJ said.

Elsewhere in the status report, the DOJ said a technical committee overseeing Microsoft's compliance has hired two consulting firms to check Microsoft's procedures for identifying communications protocols that it is required to disclose to independent software vendors who want to make their products interoperable with Microsoft's. In March, Microsoft and the plaintiffs reached an agreement to address concerns over the belated discovery of protocols that plaintiffs believed needed to be disclosed.

The technical committee will extend a royalty-free program for software vendors to receive the protocols, the DOJ said. The royalty-free program will continue 18 months after the date the committee decides the protocol documentation is substantially complete, and the technical committee can extend the program if it believe Microsoft isn't making progress on the documentation, the DOJ said.

But Microsoft is on schedule with a plan to fix technical documentation used by other software vendors, the DOJ said. Errors in the technical documentation have prompted repeated complaints from the antitrust plaintiffs in recent months, but the DOJ said Microsoft has been able "to keep up with the flow of new technical documentation issues."