High Quality Content by WIKIPEDIA articles! Background Intelligent Transfer Service (BITS) is a component of Microsoft Windows XP and later operating systems that facilitates prioritized, throttled, and asynchronous transfer of files between machines using idle network bandwidth. It is most commonly used by recent versions of Windows Update, Microsoft Update, Windows Server Update Services, and Systems Management Server to deliver software updates to clients, Microsoft`s anti-virus scanner Microsoft Security Essentials to fetch signature updates, and is also used by Microsoft`s instant messaging products to transfer files. BITS is exposed through Component Object Model (COM), making it possible to use with virtually any programming language.