To change settings for automatic updating
In Windows XP Home Edition, you must be logged on as a computer administrator to install components or modify Automatic Updates settings. In Windows XP Professional, you must be logged on as an administrator or a member of the Administrators group. If your computer is connected to a network, network policy settings might also prevent you from completing this procedure.
Windows might prompt you to restart your computer after certain components are installed. Please restart your computer when prompted; otherwise, your computer might not work properly.
If you choose not to install a specific update you have downloaded, Windows deletes its files from your computer. If you change your mind later, you can download it again by first clicking Restore Declined Updates. If any of the updates you previously declined still apply to your computer, they will appear the next time Windows notifies you of available updates.