Sometimes it may not seem like it, but each version of Windows has many of the best minds in computing working on ways to make it faster, smoother and more reliable. One of the features these guys added in Windows XP is called the "prefetch." Numbering sometimes over 100 files, this bit of programming gives XP a head start in starting up, and is supposed to reduce boot up times.
At least, in theory that's what it does. In practice, files in the prefetch can become corrupted. And that mean achingly slow boot times or even the occasional startup crash, which many XP users have become all too familiar with. Luckily, it only takes a few minutes to clean out the old prefetch files for faster load times.
Prefetch from Scratch
You can usually find prefetch with your Windows files, so search for C:\Windows\prefetch (or replace C with whatever drive you've installed Windows on). When you open the folder containing prefetch files simply select them all - then delete them all. Please note: clean the slate sparingly. Although it's perfectly safe, and recommended, to delete these files, I would only do so about once or twice a year - most computer experts think that gathering all these prefetch items is a bit taxing for your hard drive.