Do I already have SP1? Where can I get SP1? What are the major changes in SP1? What about the patches that were posted between the releases of Windows XP and SP1? How did Microsoft decide what to fix in SP1? Does SP1 offer more support for different hardware types? Does SP1 have anything to do with .NET? Is there anything else I should know about SP1?

Do I already have SP1?

To see if you already have SP1, right-click My Computer and choose Properties to open the System Properties dialog box; the General tab shows "Service Pack 1" under the System heading if SP1 has been installed.

New computers should have SP1 pre-installed, but if your computer does not yet have SP1, you can easily download and install it using Windows Update.

If you don't have a fast Internet connection, you can order the service pack on CD directly from Microsoft.

If you've purchased Microsoft Windows XP Inside Out Deluxe Edition, you'll find SP1 included on the companion CD.

The changes that are outwardly visible in SP1 are few and generally subtle. For example, in a security-related enhancement the message that appears when you download a file using Internet Explorer has been modified to provide a clearer warning of the potential dangers of downloaded files, as shown here.

The download warning in SP1 (right) provides more information about the file and a caution about files from unknown sources.

Another noticeable change in SP1 is the addition of a Set Program Access and Defaults option in Add or Remove Programs (found in Control Panel). This option, shown below, eases access to your favorite Web browser, e-mail program, media player, and other components while hiding the others.

With this new option in Add Or Remove Programs, you can specify default programs, whether they're from Microsoft or another company.

Windows XP SP1 includes a major overhaul of the Automatic Updates feature, which was first released (naturally) through Windows Update, as a Recommended Update in June 2002. In the original release of Windows XP, you could choose to be alerted when new updates were available, and Windows would download them for you to install, but the operating system wouldn't actually perform the updates. With SP1 installed, the Automatic Updates dialog box includes the option to install critical updates on a specified schedule.

In SP1, Microsoft introduced an important new security feature in Outlook Express. HTML-formatted e-mail and newsgroup messages can pose a host of problems. Pornographic spam messages, for instance, can display shocking images in your Inbox. Spam senders can confirm that your e-mail address is valid by embedding coded images in HTML-formatted messages and then checking the server logs to see which ones were downloaded in an e-mail client. You can short-circuit both types of threats by configuring Outlook Express to read all messages in plain text only. To enable this feature, choose Tools, Options, click the Read tab, and select the Read All Messages In Plain Text option.

Service Pack 1 also fixes a long-standing bug in the Outlook Express news-reading capability. Want to get rid of a message you downloaded from a newsgroup? Press the Delete key. In previous versions, pressing this key did nothing. With SP1 installed, it permanently zaps the unwanted message.

Service Pack 1 includes literally hundreds of fixes to a variety of problems and security vulnerabilities—everything from "contact information for Epson Stylus Photo is incorrect" to "unchecked buffer in Universal Plug and Play can lead to system compromise." Patches for many of these problems were available as individual "hotfixes" through Windows Update prior to SP1's release; the service pack rolls up all these patches. Although most of the fixes apply to core Windows files, some of the accessory programs included with Windows (such as Windows Messenger and Windows Movie Maker) have new versions with a handful of perceptible differences.

There were many factors contributing to this decision.  A couple of the major ones were a Windows-wide code review and data gathered from customers.

As part of Microsoft's Trustworthy Computing initiative announced by Bill Gates in January 2002, Windows XP has undergone a thorough code review. Changes resulting from this code review are incorporated in SP1.

In addition, data sent to Microsoft from customers helped the Microsoft engineers address more common problems. When a program crashes ("terminates abnormally" in polite company), the Online Crash Analysis feature offers to send information about the crash to Microsoft for examination. Although some users decline to send information because of privacy concerns, many users have participated to the benefit of all. Microsoft engineers have collected the information needed to solve many of the reported problems; these solutions are incorporated into SP1. Furthermore, they have a large sampling of data that enables them to concentrate development efforts on actual errors instead of perceived problems.

In addition to drivers for more devices than were included with the original release of Windows XP, SP1 includes support for a whole new class of devices that use Universal Serial Bus (USB) 2.0, the latest version of USB technology. Service Pack 1 also includes the underpinnings for Windows XP Media Center Edition (a version for PCs that form the hub of a home entertainment center), Windows XP Tablet PC Edition (a version for portable computers with stylus input), and Windows CE for Smart Displays (a version for portable secondary display monitors). Each of these hardware types requires Windows XP with SP1, but without the accompanying hardware and the software that comes with it, you won't see any difference in Windows XP.

At the time we put together this material, the .NET Framework, which is an optional component of SP1, is of interest primarily to software developers, who are using it as the foundation for a new generation of software applications. When those applications are more widely available, however, everyone will need the .NET Framework, which provides the common elements used by all .NET programs. The .NET Framework is roughly analogous to the Visual Basic runtime library (Vbrunxx.dll) required by most compiled Visual Basic programs.

A feature called Windows Product Activation (WPA) was implemented with Windows XP to combat software piracy—the use of unlicensed versions of Windows. With SP1, a change has been made to thwart the misuse of a particular volume license key (one that can be used an unlimited number of times) that has been widely distributed in the warez (illicit software) community. Users who have installed Windows XP using that key will not be able to install SP1, nor will they be able to install any future service packs or hotfixes from Microsoft.

Another change to WPA removes an obstacle that sometimes impeded legitimate Windows users. With the original version of WPA, if you change a number of hardware components beyond a certain threshold, Windows requires you to activate your copy of Windows (via an Internet connection or by telephone) before it allows you to log on. (This is done because Windows presumes that a computer with that many different components must be a different machine.) This immediate lockout can be a great inconvenience if it happens to occur while you're unable to activate (for example, on an airplane with no phone or Internet access) or if you're repeatedly swapping hardware in and out to troubleshoot a hardware problem. With SP1, you now have a three-day grace period for these types of situations.