Once the check is executed, any custom schedule defined by the user is reverted to the default. Moore in early 1999 was critical of this approach, describing it as "horribly inefficient" and susceptible to attacks.Microsoft stated that this ensures that users received notification of critical updates in a timely manner. In a posting to Bug Traq, he explained that, "every single Windows 98 computer that wishes to get an update has to rely on a single host for the security.
The latter is available to business editions of Windows 10 and permits postponing updates or receiving updates only after they have undergone rigorous testing.
As the service has evolved over the years, so have its client software.
Microsoft attributed the sales success of Windows 98 in part to Windows Update.
The Windows Update web app requires either Internet Explorer or a third-party web browser that supports the Active X technology.
Security fixes for Outlook Express, Internet Explorer and other programs appeared later, as did access to beta versions of upcoming Microsoft software, e.g., Internet Explorer 5.
Fixes to Windows 98 to resolve the Year 2000 problem were distributed using Windows Update in December 1998.Windows 95 and Windows NT 4 were retroactively given the ability to access the Windows Update website, and download updates designed for those operating systems, starting with the release of versions of Internet Explorer 4.The initial focus of Windows Update was free add-ons and new technologies for Windows.The tool queries the Microsoft server for a file called "", which contained a list of all the critical updates released for the operating system.The tool then compares this list with the list of installed updates on its machine and displays an update availability notification.Windows Update is a Microsoft service for the Windows 9x and Windows NT families of operating system, which automates downloading and installing Microsoft Windows software updates over the Internet.