But last week in an interview, Brad Smith, a Microsoft legal representative, said that the company would be prepared to make changes.
Microsoft was found guilty of acting as a monopoly in 2001.
Google's claims were intended to show that the world's largest software maker is not complying with a settlement agreed in 2002 that requires it to help rivals build software that runs smoothly on Windows.
Its business is regularly examined and this most recent agreement will let PC users and manufacturers set an alternative search programme, such as Google Desktop, as the default search programme.
Microsoft will also add a link to that alternate programme in the Start menu.
Currently, when Vista users search their hard drive, a Vista search box appears.
That box is to remain, and will continue to use the Microsoft search engine, but Microsoft will also add a link to the default desktop search programme.
In response to claims that Vista's "Instant Search" slows competing products, Microsoft agreed to give competitors technical information that should allow them to give their programmes higher priority in Vista.
"We're pleased we were able to reach an agreement with all the states and the Justice Department that addresses their concerns so that everyone can move forward," said Smith.
Google, however, responded that the compromise did not go far enough.
David Drummond, Google's chief legal officer, said: "Microsoft's current approach to Vista desktop search clearly violates the consent decree and limits consumer choice."
"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."
Microsoft expects the changes to be included with its first service pack for Vista, ending speculation among Microsoft-watchers that the company would do away with its practice of catchall software upgrades.
The software maker plans to release an early version of Service Pack 1 by the end of the year. A court hearing to review Microsoft's adherence to the anti-trust decree is scheduled for June 26.