To install SP3, your computer must meet the hardware and operating system requirements listed below. In addition, your computer must at least be running Windows XP with Service Pack 1 installed.

We recommended that you have Service Pack 2 installed before installing SP3. You can download Service Pack 2 at the Windows XP Service Pack 2 website.

Hardware requirements

To install SP3 on a single computer, your computer must have a CD-ROM drive and at least the following:

- A 233 megahertz (MHz) processor
- 64 megabytes (MB) of RAM
- 900 MB of available disk space during installation
- Operating system requirements

You can use SP3 to update the following operating systems:

- Windows XP Home Edition
- Windows XP Professional
- Windows XP Tablet PC Edition 2005 (Note: If you install SP3 onto a computer running Windows XP Tablet PC Edition, your operating system is upgraded to Windows XP Tablet PC Edition 2005.)

Note: the following operating systems cannot be updated using SP3:

- Windows XP Professional x64
- Windows XP Embedded

To prepare for your installation of Service Pack 3

1.) Start your computer and log on as an administrator. Administrators have complete and unrestricted access to the operating system and its settings. You can either log on with the user name Administrator, or use another account that is set up as a member of the Administrator group. To determine which group a user is set up for, click Start, click Control Panel, and then open User Accounts.
2.) If your computer is running on battery power, plug it in so that your computer does not lose power during the installation.
3.) If you use Fast User Switching, make sure all other users are logged off. For more information, see "Fast User Switching" in Help and Support Center.
4.) We recommend that you perform a full backup of the files that you keep on your computer to an external location, such as an external hard disk, DVD, CD, USB flash drive, or network folder. You can use the Backup and Restore Wizard to back up documents, pictures, and other files. For more information, see "Backing up files and folders" in Help and Support Center.
5.) If your computer is running Windows XP Professional, we recommend that you create an Automated System Recovery (ASR) set before you begin the installation. This helps repair your setup if the installation fails. For more information, see "To create an Automated System Recovery set using Backup" and "To recover from a system failure using Automated System Recovery" in Help and Support Center. (If your computer is running Windows XP Home Edition, ignore this step; ASR is not available for Windows XP Home Edition.)
6.) Close all open programs.
7.) Proceed with the installation, as described in the following section.

Important
- If the configuration of your antivirus software prevents certain system files from being changed, SP3 installation might fail. Try temporarily disabling your antivirus software. You can usually do this by right-clicking your antivirus program icon (which typically appears in the bottom right-hand corner of the computer screen) and clicking Disable.
- If you disable your antivirus software before you install the service pack, be sure that you are aware of the risks involved, and be sure to enable it after the service pack is installed.

You can install SP3 either from the Service Pack 3 CD or from the Windows XP Service Pack 3 website. The website provides a link to Windows Update, where you can install SP3.

To install Service Pack 3

1.) If you install SP3 from the Service Pack 3 CD, the Welcome to Windows XP Service Pack 3 window should automatically open when you insert the product CD. If this window does not appear, click Start, click Run, type Drive:\Autorun.exe (where Drive: is the drive letter associated with your CD-ROM drive), and then press ENTER.

If you obtain SP3 from the website, to install immediately, click Open or Run and follow the instructions on your screen. To install the program later, click Save and download the installation file to your computer. When you are ready to install the service pack, double-click the file.

2.) On the Welcome to Windows XP Service Pack 3 window, click Continue.
3.) Follow the instructions that appear on your screen.
4.) After the installation is complete, click Finish to restart your computer.
5.) If you disabled your antivirus software, enable it again.

You can use Add or Remove Programs to remove SP3 and restore your computer to its previous state.

To remove Service Pack 3 by using Add or Remove Programs

1.) Click Start, and then click Control Panel.
2.) Click Add or Remove Programs, click Windows XP Service Pack 3, and then click Remove.
3.) Follow the instructions that appear on your screen.

Important
- If you choose to remove SP3, a dialog box displays a list of the programs that you installed after you installed SP3. If you continue with the removal, these programs might not work correctly.

To find additional information, such as release notes and the SP3 deployment guide, go to Windows XP Service Pack 3 Resources on the Microsoft TechNet website.