Microsoft is making a special exception in the way it retires Windows XP in China, and will continue offering security support for the OS to users in the nation.To do so, the U.S. software giant is partnering with China's leading Internet security vendors, Microsoft said in a Sunday posting on its official account with Sina Weibo, a top social networking site in the country.Outside of China, Microsoft is dropping support of Windows XP on April 8, meaning that users of the OS will no longer receive security patches meant to fix vulnerabilities in the software.To stay protected, Microsoft has urged users of the old OS to upgrade their PCs to the latest version of Windows. In markets such as the U.S., Windows XP is gradually being phased out by PC users. But in China, the software remains one of the top operating systems.Among China's Internet users, about 57 percent rely on Windows XP systems to go online, according to analytics site CNZZ.com. The OS can still be found in use at Internet cafes, businesses and schools.A major reason why the 12-year-old OS is so popular in China is because it has been widely pirated. For years, Microsoft has tried repeatedly to convince consumers and businesses in the nation to buy official copies, pointing to the rampant security vulnerabilities found in bootleg versions. But the operating system's high price has been one factor that's turned potential buyers away.The retiring of Windows XP, however, is giving China's security vendors a chance to fill the void with their own security products. Among the Chinese security vendors helping Microsoft provide support to the OS is Tencent, one of China's largest Internet firms.It's unclear how the protection will be delivered, but the security support may not even matter to most Windows XP users in the country.In its Sunday post, Microsoft noted that 70 percent of China's Windows XP users had in the last 13 years never chosen to install the company's security updates.