text: 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 , enabling instead 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 .
simplified: Microsoft Update is a feature in Windows Update that provides updates not only for Windows but also other Microsoft software ( such as Microsoft Office ) .