Top Alternatives to Service Pack 1 for Windows XP for Windows
Get Started with An Essential Windows XP Improvement
Service Pack 1 for Windows XP (or Windows XP SP1 as its reputation has it) is an essential software upgrade for Windows XP. It patches up many large security holes adds new capabilities improves XP's built-in software and integrates most of the major security improvements XP saw from its release on. Also as you'd expect from such a key update to an operating system it's free.