"The top-down push is very strong," said Duncan Clark, chairman of BDA China Ltd, a Beijing-based consultant to technology companies.

"While it used to be that nobody ever got fired for buying IBM, now that's switching to: everybody gets fired for buying IBM."

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Inspur's Hong Kong-traded unit, Inspur International Ltd, lists Samuel Shen, the chief operating officer of Microsoft's Asia-Pacific Research and Development Group, as a nonexecutive director. Microsoft, which invested $25 million in the company in 2005, redeemed the remainder of its preferred shares in December and currently isn't listed as a shareholder, according to data compiled by Bloomberg.

In its 2013 annual report, Inspur International said it maintained "close cooperation" with strategic partners including Microsoft.

Joanna Li, a Beijing-based spokeswoman for Microsoft, didn't immediately respond to an emailed request for comment and couldn't be reached by mobile phone.

IBM's China spokesman, Anthony Guerrieri, didn't immediately respond to a request for comment on Inspur. In a statement on Wednesday, Armonk, New York-based IBM said it has been a trusted partner in China for more than 30 years and wasn't aware of any government policy recommending against the use of its servers.

The member of Inspur's marketing department said the company had hired employees from IBM's Systems and Technology Group and its business process outsourcing department.

Inspur's predecessor, Shandong Electronic Equipment Factory, began producing computer peripherals and low-frequency tubes in the 1960s, according to Inspur Group's website. China's first space satellite, launched in 1970, used Inspur transistors.