A Chinese anti-trust regulator has given Microsoft20 days to reply to queries on the compatability of its Windows operating system and Office software suite. The State Administration for Industry and Commerce (SAIC) questioned Microsoft Vice President David Chen and gave the company a deadline to make an explanation, the agency said in a short statement on its website.

SAIC suspectsMicrosoft has not fully disclosed issues relating to the compatability of the software and the operating system.

Microsoft said it was "serious about complying with China's laws and committed to addressing SAIC's questions and concerns".

In related news, Microsoft will close its Windows Live Messenger (MSN) service on the Chinese mainland by October 31, the Beijing Morning Post reported on Monday

Skype has emailed Chinese MSN users about the change, suggesting they move to the VoIP (Voice-over-internet Protocol) service.

Except for the Chinese mainland, Microsoft pulled the plug on the MSN service globally on April 8, 2013.