Reuters reports that four consumer groups in the United States have accused Microsoft of once again using anti-competitive tactics with the upcoming release of Windows XP — the company’s next-generation operating system. “Activities such as communications, commerce, streaming audio/visual applications, and on-line services are, at the present, vigorously competitive,” the groups said in a statement. “These essential areas of the 21st Century economy will be threatened, and consumers harmed, if Windows XP and its tightly bundled version of Internet software hits shelves as planned.”