US search engine Google is reported to have complained to competition authorities that Microsoft's Windows Vista operating system software puts rivals at an unfair disadvantage.
The Wall Street Journal said Google sent a 50-page paper to the US Justice Department and state attorneys general in April, alleging that Microsoft's latest version of its operating system violates the software giant's competition settlement.
In its white paper, Google alleged that Vista makes it difficult for consumers to use rival desktop search applications, such as the applications provided by Google and others.
Desktop search is software that allows users to scan the contents of their computer hard drives, e-mails and other data.
Google's allegations are under review by the Justice Department and state attorneys general who were parties to a consent decree that resolved the US government's case against Microsoft in 2002. Microsoft rejected Google's allegation that the Vista desktop search violates the settlement.
