Microsoft Corp. v. AT&T Corp.

AT&T Corp. (plaintiff) owned a patent on speech-processing software and sued Microsoft (defendant) for infringement based on software in Windows that performed the patented function once installed on a computer. Microsoft sent master disks of Windows from the United States to foreign manufacturers, who made copies and installed those copies, rather than the original disks, on computers sold abroad. AT&T argued this transmission of master disks constituted supplying components from the United States for combination abroad under 35 U.S.C. section 271(f); the district court agreed, and the Fifth Circuit affirmed. The Supreme Court granted certiorari.