Keep your operating system updated: Frequently asked questions

Microsoft will periodically release software updates for Windows that you are entitled to under your software license. Microsoft may also provide updates to other hardware and software components on your computer, (supplied by the manufacturer) which improve their performance or reliability.

Windows Update determines what updates are applicable to your computer and can download and install them according to user preferences. Examples of updates include patches, security updates, service packs, version upgrades, drivers, or other types of updates. These updates can improve an existing component or provide new features.

If you use Windows Vista, Windows XP Service Pack 2 (SP2), Windows XP, Windows 2000 Service Pack 3 (SP3) or later, or Windows Millennium Edition (Me): Configure your settings in your Control Panel to deliver updates to your computer automatically. This is the easiest and most reliable way to make sure that you get new security updates as soon as they become available.

To turn on or check your automatic updating settings, click the link that corresponds to the operating system you use.

If you use Windows 2000 SP2 or earlier, Windows 98, Windows 95, or Windows NT Workstation 4: You can go to Windows Update for the latest security updates. (Make sure to return monthly.)

Yes. Each Microsoft security update addresses a specific issue. Unless you install the update, you will not be protected from that particular issue.

Not yet. When you download the update files, you only save them to your computer. You then have to install them to enable them them to go to work to help protect your computer.

If you use Microsoft Update or Microsoft Office Update, the updates you select are downloaded and installed at the same time. If you have configured your settings to download updates but not install them, you will get a notice like the following when the updates have downloaded:

New updates are ready to install. This notice appears after the download is complete. If you see this notice, don't delay. Click the balloon to install the updates right away.

Whenever major security updates are released, Microsoft sends instant message, RSS, or e-mail alerts to subscribers of our free notification service.

Learn how to get notified about security alerts.

The Microsoft Security Response Center (MSRC) has developed a rating system to help customers determine which updates to install first. The severity rating system provides a rating from "low" to "critical" for each computer security alert. All MSRC security updates are provided at Microsoft Update and Windows Update.

Learn about the severity rating system.

Automatic updating is the easiest, most reliable way to help protect your computer from the latest Internet threats by having security updates delivered right to your computer automatically.

When your computer is connected to the Internet, automatic updating analyzes the Microsoft software installed on your computer and checks for any Important/High-Priority updates you need—both current and past.

It then downloads the updates for you and installs them at the time you choose. (This usually happens in the background so it doesn't interfere with your use of the computer.) Whenever you reconnect your computer to the Internet, Windows repeats this process.

In Windows Vista, you control the automatic updating settings through the Windows Update Control Panel. For more information, see Turn automatic updating on or off.

If you use Windows XP or Windows 2000 Service Pack 3 (SP3) or later: Visit Microsoft Update and look for the >Automatic Updates box on the right side of the screen. Click the button that says Turn on Automatic Updates. If Automatic Updates is already turned on, you can adjust your settings by clicking Pick a time to install updates.

When you set up automatic updating, we strongly recommend that you set it to be as automatic as possible, directing Windows to download updates and install them on a schedule you specify. This gives you the greatest assurance that security updates are installed on your computer as soon as they're available.

If you use Windows 2000 SP2 or earlier, Windows 98, Windows 95, or Windows NT Workstation 4: You can go to Windows Update for the latest security updates. (Make sure to return regularly.)

Automatic updating usually doesn't slow your computer because it works in the background. If you prefer, you can control when your computer automatically updates. For example, you can leave your computer on and connected to the Internet, and schedule updates for very early morning or another time you're unlikely to be using it.

In Windows Vista, you control the automatic updating settings through the Windows Update Control Panel. For more information, see Turn automatic updating on or off.

If you use Windows XP or Windows 2000 Service Pack (SP3) or later: Visit Microsoft Update and look for the Automatic Updates box on the right side of the screen. Click Pick a time to install updates.

To turn off Automatic Updates, click More Options and then click Turn off Automatic Updates. We do not recommended doing this.

All of these are Microsoft services designed to improve the security and reliability of your computer. Each is used to keep different versions of Microsoft Windows and Microsoft Office up to date.

Microsoft Update is a service that helps you keep Microsoft Windows, Microsoft Office, and other programs current.

Windows Update is a service that helps you keep Microsoft Windows current. It supports Windows Vista, Windows XP, Windows 2000 SP3 or later, Windows Server 2003, Windows 2000 SP2 or earlier, Windows Me, Windows 98, Windows 95, and Windows NT Workstation 4.0 current.

Automatic Updating is a feature that automatically delivers the latest high-priority updates to your computer for both Microsoft Update and Windows Update.

Microsoft Update offers an efficient, easy way to keep Microsoft Windows, Microsoft Office, and other Microsoft programs current. When you visit the Microsoft Update Web site, it analyzes your system for what it needs and tailors its recommendations to the Microsoft software installed on your PC. These include:

Microsoft Update supports Windows Vista, Windows XP, Windows 2000 Service Pack 3 (SP3) or later, and Windows Server 2003. It provides updates for Microsoft Office 2007, Microsoft Office XP, Microsoft Office 2003, Microsoft SQL Server, and Microsoft Exchange Server. Updates for more Microsoft programs will be added in the future.

Tip: For more information, read a comprehensive list of questions and answers about Microsoft Update.

No, it helps you keep certain versions of Microsoft Windows, Microsoft Office, and other Microsoft software current.

Go to Help keep your computer's defenses current with Microsoft Update, and follow the directions in "How to sign up for Microsoft Update." We recommend that if you are not enrolled in Microsoft Update, you go to Windows Update and follow the instructions on the screen to sign up. This will allow you to receive updates from Windows and from other Microsoft products such as Microsoft Office.

Windows Update offers an easy, efficient way to keep Microsoft Windows current. When you visit the Windows Update Web site, it analyzes your system, tailoring its recommendations to the Windows operating installed on your computer.

Windows Update supports the versions of Windows that Microsoft Update does, as well as Windows 2000 Service Pack 2 (SP2) or earlier, Windows Me, Windows 98, and Windows 95. (Windows Update also supports Windows NT Server 4.0. and Windows NT Workstation 4.0.)

Note: In Windows Vista, the Windows Update Web site has been replaced by the Windows Update Control Panel. For more information, see Understanding Windows automatic updating.

Go to Windows Update, and follow the directions on the screen.

Click the following link that corresponds to your version of Microsoft Office, and then follow the directions given:

Tip: If you don't know what version of Office you are using, from the Help menu of any program, choose About <program name>. The top line will tell you which version of Office you are using.

Important on Windows Vista and high-priority updates on windows XP and earlier are critical to the security of your computer—for example, fixes that help protect against security threats—or boost its reliability. Without these security updates, your computer may be more vulnerable to attack from cyber crooks and malicious software.

Recommended updates (only on Windows Vista) help keep your computer running smoothly or simply make using it more fun with, for example, the latest versions of Windows Media Player or Windows MovieMaker.

Optional updates are not downloaded or installed automatically. Windows Update provides them for you to review. These updates may include new software components or applications from Microsoft or its partners to enhance your computing experience.

Yes, because they are two completely different Microsoft programs. However, if you're using a version of Windows that Microsoft Update supports, Microsoft Update will help you bring Microsoft Office up to date as well.

If you log off of the Internet or shut down your computer during a download, the download will be suspended, but resumed the next time your computer is online.

A service pack is an update to software that addresses certain known vulnerabilities and delivers product enhancements—for example, Windows XP with SP2. So, when you use Microsoft Update or Windows Update, after it scans your system, it may recommend that you install a service pack if the analysis reveals that your computer needs it.

To tailor updates for your system's needs, the information Microsoft uses includes the following:

Windows also records your Internet Protocol (IP) address when you connect to the Update site, but this address is only used for aggregating statistics.

To learn more about your privacy in this process, read the full Windows Update or Microsoft Update privacy statement. If you have any further questions about how Microsoft update services protect your privacy, please send e-mail to privhelp@microsoft.com.