AT&T Corporation (plaintiff) owned a patent disclosing software for digitally encoding and compressing recorded speech. AT&T brought an infringement suit against Microsoft Corporation (defendant) based on software incorporated into Microsoft’s Windows system that enabled speech processing in the manner claimed by AT&T’s patent, when installed on a computer. As part of Microsoft’s manufacturing and sale process, Microsoft sent master disks of the Windows program to foreign manufacturers, who made copies of the software. The foreign manufacturers subsequently installed the copies on computers to be sold abroad. AT&T argued that Microsoft’s initial transmission of the Windows master disks to foreign manufacturers constituted Microsoft supplying from the United States components of AT&T’s patented speech processor for combination abroad, under 35 U.S.C. § 271(f). The district court concluded that Microsoft had, in fact, infringed the patent under § 271(f). The United States Court of Appeals for the Fifth Circuit affirmed. Microsoft filed a petition for certiorari. The United States Supreme Court granted the petition.