Microsoft released documents on Wednesday that detail changes it will make to its desktop search and indexing feature in Windows Vista that will be included as part of the Vista SP1 (Service Pack 1) update.

The changes are a response to charges from rival Google that Microsoft built the feature in such a way that it slowed down competitive offerings from rivals.

Microsoft agreed to make the changes as part of its ongoing antitrust proceedings with U.S. and state officials, and they were detailed as part of a status report filed in the case in June. To provide more information to the general public, the company posted documents online Wednesday that detail how third parties can help modify desktop search applications to work with the changes being made in SP1. Microsoft has said it will release SP1, a roll-up of updates to the Vista OS, in the first quarter of 2008.

Microsoft said it made the changes so that a customer who uses a third-party desktop search product instead of Vista's built-in feature can have "easy and direct access" to those offerings through the Windows user interface. "That means that in addition to the numerous ways a user could access a third-party search solution in Windows Vista, they can now get to their preferred search results from additional entry points in the Start Menu and Explorer Windows in Windows Vista SP1," the company said.

These features were at the heart of Google's claims, which appeared in a white paper to U.S. and state antitrust officials in April. Google said the desktop search feature in Vista discouraged users from installing third-party products because Vista's search boxes and bars -- available in several places in the OS, including the Start menu and in the Windows Explorer file manager -- work only with Microsoft's search and indexing tool. The company also said it is nearly impossible to turn off Vista's indexing, which means a competitor must add a second indexer that slows down a PC.

To let their products use Vista options they don't have access to now, third-party vendors can register their search applications using the new search protocol in Windows Vista SP1, which is detailed online. An article explaining the search changes can be found in Microsoft's Knowledge Base.