Windows XP Service Pack 3 is a service pack that is cumulative back to the last currently-supported service pack. This means that Windows XP Service Pack 3 contains all the fixes that were included with Windows XP Service Pack 2 (SP2). If you have already installed Windows XP Service Pack 3 (SP3), you do not have to install Windows XP SP2.
Note You must have either Windows XP Service Pack 1a or Windows XP Service Pack 2 installed in order to install Windows XP Service Pack 3.
How to obtain
You can use Windows Update or the Microsoft Download Center to obtain Windows XP Service Pack 3 (SP3).
Check for updates on Windows Update
1. Visit the following Microsoft Web site: http://windowsupdate.microsoft.com
2. Click Express Install (Recommended).
3. If your computer qualifies, Windows XP SP3 will be one of the updates that are automatically selected. Click Install.
4. Review and accept the End User License Agreement (EULA).
Windows XP SP3 will be downloaded to your computer, and the Windows XP Service Pack 3 Setup Wizard will help you install it.
Obtain the latest Windows XP service pack from the Microsoft Download CenterIf you have trouble obtaining the service pack from Windows Update, you can obtain the standalone update package from the Download Center.
The following file is available for download from the Microsoft Download Center:
Download the Windows XP Service Pack 3 package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=5B33B5A8-5E76-401F-BE08-1E1555D4F3D4)