Microsoft Corp. filed a patent-infringement complaint with the U.S. International Trade Commission against Belkin Corp. for importing products the software company claims infringes on a patent it holds for peripheral device technology. According to Microsoft, Belkin uses a technology called "U2" in several of its mouse products, which enables a computer peripheral device to auto-sense whether the device is plugging into a PS2 or USB port on a computer and to connect to it.