He added the agency, one of the government bodies which enforces China's anti-monopoly law, was also looking into "issues" with Microsoft's media player and browser, according to a transcript posted online. Microsoft has previously faced anti-trust investigations in other markets for tying the company's Windows system to its other products. The European Commission fined it $731 million (R7.8 billion) in March last year for failing to offer users browser choices beyond its own Internet Explorer. "Through repeated contact with Microsoft, their top-level executives have shown respect for China's laws, (and) cooperated with China's anti-monopoly investigation," Zhang said. Microsoft has said it seeks to comply with Chinese law. Its comments came after the official announcement of the investigation, which included raids on its offices in the country.