Microsoft China announced last week that it had initiated legal proceedings against nine computer retailers in China over preinstalled pirated Windows operating systems.

The retailers in seven Chinese cities including Beijing, Shenzhen, Guangzhou and Nanjing sold Lenovo, Dell, Acer and HP computers already loaded with illegal software, according to the complaint.

Microsoft also unveiled the result of a test on more than 100 computers with pirated Windows operating systems that found 94 percent were infected with malicious software.

"We want to send a clear message that piracy in PC sales is not only theft of intellectual property, but also poses serious security risks to consumers," said Tim Cranton, Microsoft's chief legal officer for the China region.

"We believe that these lawsuits will serve as a wake-up call to other PC resellers who fail to respect intellectual property rights," he said, adding that his company will cooperate with computer makers to promote genuine software to create safer experience for users.

It is not the first time the computer giant has waged legal campaigns against piracy in China.

In January, the company sued Shanghai Gome, a branch of one of the nation's largest electronics and appliance chains, and Beijing Chaoyang Buynow, one of China's largest computer malls. Microsoft said it had evidence that pirated copies of Windows and Microsoft Office were preinstalled on computers sold by the two stores.

In 2008, Microsoft filed complaints with the National Copyright Administration and the Ministry of Public Security against tomatolei.com, which it said offered pirated Windows operating systems for free download. Hong Lei, the founder of the website, was later sentenced to three and a half years in prison and fined 1 million yuan ($156,800).

Since the launch of the State Council's anti-piracy campaign, "we have observed the government's strengthened efforts to protect IPR", said Wu Gaohan, standing director of the Society of Consumer Protection and Law.

"We are pleased to see Microsoft is proactively cooperating with the government in resolving the problem of piracy in PC sales," he said. "It is an important step in protecting Chinese consumers and bringing improvements to China's IPR environment. It is paramount in making a safe digital community."

International copyright organization Business Software Alliance said last year that China's software piracy rate was 77 percent, but Chinese IT consultancy China Labs said the number was only 38 percent, a decline from 45 percent in 2009.

"Around 80 percent of Microsoft's income in China comes from anti-piracy," said Fang Xingdong, a Chinese Internet expert and a founder of China Labs. "For Microsoft, fighting piracy is even more profitable than selling genuine software."

Contact the writer at zhangzhao@chinadaily.com.cn.