China has long been both a huge lure and a thorn in the side for Microsoft. Massive piracy of Windows XP, a decade-long effort to replace Windows entirely with a home-grown Linux variant called Red Flag and an OpenOffice variant called RedOffice, and a ban on Windows 8 for government use following the leak by former NSA contractor Edward Snowden of information on National Security Agency spying all have combined to hinder Microsoft in the Chinese market. But now Microsoft—in partnership with the state-owned China Electronics Technology Group (CETC)—is preparing to reboot its relationship with Beijing, thanks to a modified version of Windows produced specifically for China, Dow Jones Newswires reports.

CETC, which develops technology for the Chinese government and military, owns a 51 percent stake in a joint venture with Microsoft called C&M Information Technology Co. Ltd. The new operating system created by the venture is in testing at three government pilot sites; Xiong Qunli, chairman of CETC, told Dow Jones’ Eva Dou and Yang Jie that the venture was “beginning the sales process” with the Chinese government.

Windows 10 is already widely available to consumers in China. But Windows is still banned for government systems—and given the reach of the Chinese government into all things, that means Windows has been largely excluded from the enterprise market in China. The custom version developed under the joint venture is essentially a custom image of Windows 10 at its core, with a set of policy settings hard-coded for government users. It’s not clear if additional code is being added to the image.