Microsoft Corp said it has filed complaints with the copyright bureau against Beijing Zhong Xin Lian, Tianjin Tian Bao Guang Die and Tianjin Minzu Wenhua Guang Die for unauthorized copying of its software. The bureau said it would seek to prosecute if it is found that any of the three copied and sold software without Microsoft's clearance. One company is alleged to have been making 20,000 pirated disks a day. A source called the evidence glaring. The fake makers, suspected of shipping disks into the US, may have links with the military and other groups, reports said.