High Quality Content by WIKIPEDIA articles! Windows Update is a service provided by Microsoft that provides updates for the Microsoft Windows operating system and its installed components, including Internet Explorer. An optional feature disables access to Windows Update and replaces it with access to Microsoft Update, an expanded version of the service which provides updates not just for the operating system and Internet Explorer, but also for other Microsoft software running under Windows, such as Microsoft Office, Windows Live applications, and Microsoft Expression Studio. Updates are normally provided over an Internet connection, although there is provision for updates to be installed on computers without an Internet connection.