Windows Update is the online extension of Windows from which you can download items such as security fixes, critical updates, the latest Help files, drivers, and Internet products. New content is added to the site regularly, so you can always get the most recent updates and fixes to protect your computer and keep it running smoothly.

Windows Update scans your computer and provides you with a tailored selection of updates that apply only to the items on your computer.

Any update that Microsoft considers critical to the operation of your operating system, programs, or hardware is classified as a "critical update" and is automatically selected for you to install when you go to Windows Update. Critical updates are provided to help resolve known issues and protect your computer from known security vulnerabilities.