Download Windows XP Service Pack 3

If you have turned on automatic update, than your system will automatically download all updates and install it. But if you have slow internet connection, or you reinstall your windows XP frequently or you have many system in network, or have any problem obtaining the service pack from Windows Update than you might need SP3 offline setup. Below is the link to download windows XP SP3 from Microsoft download center. This is a stand-alone update package.