China has banned government use of Windows 8, Microsoft's latest operating system, a blow to a US technology company that has long struggled with sales in the country.
The Central Government Procurement Centre issued the ban on installing Windows 8 on Chinese government computers as part of a notice on the use of energy-saving products, posted on its website last week.
The official Xinhua news agency said the ban was to ensure computer security after Microsoft ended support for its Windows XP operating system, which was widely used in China.
"We were surprised to learn about the reference to Windows 8 in this notice," the company said in a statement. "Microsoft has been working proactively with the Central Government Procurement Centre and other government agencies through the evaluation process to ensure that our products and services meet all government procurement requirements."
"We have been and will continue to provide Windows 7 to government customers. At the same time we are working on the Window 8 evaluation with relevant government agencies," Microsoft said.
Neither the government nor Xinhua elaborated on how the ban supported the use of energy-saving products or how it ensured security.
China has long been a troublesome market for Microsoft. Former CEO Steve Ballmer reportedly told employees in 2011 that, because of piracy, Microsoft earned less revenue in China than in the Netherlands even though computer sales matched those of the United States.
Last month, Microsoft ended support for the 13-year-old Windows XP to encourage the adoption of newer, more secure versions of Windows. This has potentially left XP users vulnerable to viruses and hacking.
"China's decision to ban Windows 8 from public procurement hampers Microsoft's push of the OS to replace XP, which makes up 50 percent of China's desktop market," said data firm Canalys.