If you've downloaded a Windows XP SP3 ISO image, you can verify its integrity using the following MD5 hash:
Windows XP Service Pack 3 (SP3) is the third major update for Windows XP, released on April 21, 2008. It includes all previously released updates for Windows XP, as well as some new features and improvements.
595f4f6a464e0708e5c97c9c314a6c42