Many of the restrictions are due to expire Nov. 12, and last week several U.S. states filed motions in favor of extending them for a further five years. Four of those states -- New York, Maryland, Louisiana and Florida -- had previously said they opposed an extension.
The DOJ had also opposed the extension, and on Friday it made it clear that it would not be making a turnabout like the four U.S. states.
"The United States will not file a motion to extend its Final Judgment as it does not believe that the standard for such an extension has been met," the DOJ said in a court filing with the U.S. District Court, District of Columbia.
The restrictions were part of the 2002 "consent decree" that settled the U.S. government's case against Microsoft. They prohibit Microsoft from retaliating against PC makers that install its competitors' software, or licensing its software to them on unequal terms.
Another requirement -- that Microsoft license its APIs (application programming interfaces) to let rival products interoperate with Windows -- has already been extended for two years.
The DOJ didn't explain its decision Friday. In August it said it felt the judgment had been successful in preventing Microsoft from continuing its exclusionary behavior.
The states who favor an extension disagree. They say operating systems haven't evolved as quickly as people thought they would in 2002, and that Microsoft could still use the dominance of Internet Explorer to choke competitors in the emerging Web 2.0 world.
A status hearing that will likely address extending the restrictions is scheduled for Nov. 6 with District Court Judge Colleen Kollar-Kotelly.