Microsoft's Windows Vista OS doesn't pose antitrust issues so far, according to the latest status report on Microsoft's compliance with the US antitrust settlement.

The company has addressed all of the bugs identified relating to how third-party middleware software interacts with Vista, according to the report, filed in US District Court in Washington, DC.

Microsoft had increased its cooperation with the court's technical committee in several ways to help ensure middleware vendors had their software ready for Vista before the OS ships, the report said.

The document defines middleware as software programs such as instant messaging programs, media players, email clients and Internet browsers.

About 30 vendors are working with regulators and Microsoft on how their software works with Vista, the report said. The US government and states that were a party to the antitrust suit against Microsoft had conducted extensive testing of interim builds of Vista and Internet Explorer 7 to ensure compliance with the November 2002 antitrust settlement, the report said.

As part of that settlement, Microsoft agreed to license communication protocols to IT vendors interested in developing server software that works smoothly with its Windows operating system.

After complaints, Microsoft is rewriting some of the technical documentation for its Microsoft Communications Protocol Program (MCPP).

The status report said Microsoft had made the new documentation easier to understand, but the company needed to stay on schedule for delivering further documents.

Microsoft has until November 2009 to provide the information.

The European Commission has also been scrutinising Vista, following its 2004 antitrust ruling against Microsoft. So far, the Commission has taken no action against Vista. Microsoft has warned that if regulatory interference delays Vista's European launch, it could hurt Europe's economy.

Microsoft plans to release Vista to business customers on November 30.

In 2004, the Commission fined Microsoft Euro 497 million ($US613 million at the time) for abusing its monopoly in the desktop OS market, ordered it to release a version of Windows XP without Windows Media Player software, and mandated it to license and document protocols used by its server products. Microsoft is appealing the decision before the European Court of First Instance in Luxembourg.