Windows Update is a service provided by Microsoft for users of Microsoft Windows. It provides updates for the operating system and its installed components. Microsoft Update is an optional feature that can be enabled to provide updates for other Microsoft software installed on a Windows computer, such as Microsoft Office, Windows Live applications, and Microsoft Expression.
Security updates are delivered by the Windows Update service on the second Tuesday of each month. However, security updates can be delivered whenever a software update is required to prevent an exploit targeting Windows users. Windows Update can be configured to automatically install updates, ensuring that a computer is always up-to-date and not vulnerable to computer worms and other such malware.
The Windows Update site was first introduced with the launch of Windows 98. Since then the site has gone through several revisions.
In 2002, Microsoft released Software Update Services, a server component that could be installed on Windows 2000 Server systems to enable downloading and distribution of security patches for an entire company through a central server. Windows Me introduced Automatic Updates which made it possible to schedule and automatically download and install security updates in the background without using the browser. Windows 2000 Service Pack 3 included BITS, a new client-side component to facilitate Automatic Updates which is available as a download for Windows 2000.[1]
File:Windows Update v3.pngWindows Update version 3 in Windows 98Windows Update in Windows Me
In late 2004, Microsoft released Windows Update 5 for Windows XP, which includes Service Pack 2 and several major changes to the update application. Users without broadband access can order a CD of XP Service Pack 2 (SP2) from the Microsoft website; while the CD was at one time completely free of charge, as of July 2006 there is a small charge for shipping (the packaging encourages sharing the CD with other users of Windows XP). After installing SP2, one should then go to the Microsoft website to check for newer updates—dozens have been released since SP2.
In Windows Vista and Windows Server 2008, the web site is no longer used to provide a user interface for selecting and downloading updates. It has been replaced with a Windows Update control panel that provides similar functionality.
Updates requiring a reboot would pop up a dialog box requesting that the user reboot their machine every number of specified minutes.[2]
While Windows Update will still require reboots for certain classes of updates, this dialog box was changed to allow the user to select a longer period of time (up to 4 hours) before being prompted again. The revised dialog box also displays under other applications, instead of on top of them.
Windows Update can automatically download and install both Important and Recommended updates. Updating occurs in the background, and flexible options are provided for completing the updating process. If an update requires a restart to complete installation, the update can be scheduled for a specific time. You can also postpone a previously scheduled restart until your current work is complete. If a software update applies to a file in use, Windows Update can save the application's data, close the application, update the file, and then restart the application.
Windows Update also makes use of Transactional NTFS, a file system feature introduced with Windows Vista, when performing updates to Windows system files. This feature helps Windows recover cleanly in the event of an unexpected shut-down during an update, as the transactioning system will ensure that changes are committed to the file system in an atomic fashion.[3]
Alternatives
Prior to Windows Vista, Windows Update must be run from Internet Explorer.
Another method that is commonly used by those that wish to avoid using Internet Explorer, is to use the IE Tabextension for Mozilla Firefox, which allows for a page to be rendered using the IE engine within a tab in the Mozilla Firefox browser.
Although these alternatives exist, the most efficient and supported method is to simply use Internet Explorer, even if that means using Internet Explorer only for using the Windows Update functionality.
