ah, you mean this;
Prefetcher Tweak
(by Crapito)
This is an unique technique for XP, which could improve the performance significantly by tweaking the prefetcher. Recommended hardware: PIII 800 or higher, 512M RAM or more.
1. run "regedit";
2. go to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\EnablePrefetcher
3. Set the value to either 0-Disable, 1-App launch prefetch, 2-Boot Prefetch, 3-Both ("3" is recommended).
4. reboot.
It will decrease the boot time but double and increase the performance of your XP. Try it!
...mine was already set to 3...I think that's the default