Windows XP, Windows 2000 and Windows Millennium Edition users
It's very important for you to configure your PC to perform automatic updates to Windows. The Automatic Update service will help to ensure that the most critical security patches are installed as they become available.

Operating system patches and updates frequently require that your computer be restarted before they are fully installed. If a restart is needed, Automatic Update will give you the option to restart immediately, or to wait until a more convenient time. If you choose to wait, please be sure to restart as soon as possible.

Also be aware that in most cases it's best to shut down your computer when it won't be used for several hours, as at night, unless some automatic process like a back-up or scheduled software update must run in your absence, or if you need to connect to it remotely.

Win2K and WinME -- Turn On and Use Automatic Updates

1. From Start --> Settings --> Control Panel, double-click Automatic Updates, and then click to select the Keep my computer up to date option.

2. Choose this option: Automatically download the updates, and install them on the schedule that I specify.

Once Automatic Updates are enabled, you can select the day and time for scheduled updates to occur. Remember the computer must be ON for the automated updates to work.

For more information:

How to Configure and Use Automatic Updates in Windows 2000
How to Configure and Use Automatic Updates in Windows Millenium Edition

WinXP -- Turn On and Use Automatic Updates

1. From Start --> Settings --> Control Panel, select (or double-click) System.

2. Click the Automatic Updates tab, and then click to select the Keep my computer up to date option.

3. Choose this option: Automatically download the updates, and install them on the schedule that I specify.

Once Automatic Updates are enabled, you can select the day and time for scheduled updates to occur. Remember the computer must be ON for the automatic updates to work.

For more information:

How to Configure and Use Automatic Updates for Windows XP

Automatic Update is not available for Windows 98 or NT. Windows 95 is no longer supported by Microsoft.