The Prefetch folder is used to increase the speed in loading times for applications that have already been executed.  There are several problems with thought process.  The folder is never purged leaving old and unwanted clutter in that folder that will eventually slow down the computer.  Another annoyance, is that this is yet another folder that maintains tracking of what you do on your computer.  There are many methods of removing this data.  Freeware applications such as CCleaner or Windows XP Prefetch Clean And Control 1.2.0.  However, sometimes a script is what is needed to implement using Group Policy or some other method.  This script is applicable for Windows XP and Windows 2003.

Dim fso
Set fso = Createobject("Scripting.FileSystemObject")
fso.DeleteFile("C:\WINDOWS\Prefetch\*.*")

Disclaimer:  I am not going to write a disclaimer for all such scripts; however, I am not the genious who created this script.  I find things from time to time and have tested and used these scripts.