Instructions: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Input: In May 2014, the Government of China banned the internal purchase of Windows 8-based products under government contracts requiring "energy-efficient" devices. The Xinhua News Agency claimed that Windows 8 was being banned in protest of Microsoft's support lifecycle policy and the end of support for Windows XP (which, as of January 2014, had a market share of 49% in China), as the government "obviously cannot ignore the risks of running OS [sic] without guaranteed technical support." However, Ni Guangnan of the Chinese Academy of Sciences had also previously warned that Windows 8 could allegedly expose users to surveillance by the United States government due to its heavy use of internet-based services.
Output:
When did the Chinese government ban the purchase of Windows 8 products?