Internet search leader Google is trying to convince US federal and state authorities that Microsoft's Vista operating system is stifling competition.
In a 49-page document filed April 18th with the US Justice Department and state attorneys general, Google alleged that the latest version of Microsoft's Windows operating system impairs the performance of "desktop search" programs that find data stored on a computer's hard drive.
The Vista operating system, which became widely available in January, includes a desktop search function that competes with a free program Google introduced in 2004. Several other companies also offer desktop search applications.
Besides bogging down competing programs, Google alleged Microsoft had made it too complicated to turn off the desktop search feature built into Vista.
Google hopes to show that Microsoft isn't complying with a 2002 settlement of an antitrust case that concluded the world's largest software maker had leveraged the Windows operating system to throttle competition.
The consent decree requires Microsoft to ensure its rivals can build products that run smoothly on Windows - something that Google says isn't happening.
Microsoft said it already has made more than a dozen changes to address regulators' concerns about Vista and pledged to address any other legitimate problems.
"While we don't believe there are any compliance concerns with desktop search, we've also told officials we are committed to going the extra mile to resolve this issue," Microsoft spokesman said.