Handy Software Lab Products Knowledge Base

2.????? Defragging the Prefetch File:

3.????? Cleaning out the Prefetch Files:

4.????? Repairing the Prefetch Folder:

?

?

Prefetch Parameters

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters]

"EnablePrefetcher"=dword:00000003

?

1. The Windows Prefetcher Guide:

One of the hidden features in Windows XP (only) is the prefetcher. It, quite simply, works to speed up the launch of applications by loading them before you access them. It primarily works by loading startup programs during the time windows is still booting so that when you enter your password, everything loads quickly. It also keeps a record of all programs launched and how much they are used to aid in allocating how much prefetching to which program.

?The prefetcher works to take all the loading to the windows boot logo stage to make everything else that requires your interaction faster.

The prefetcher has a file for each program that you run that, in part, records the amount of use. Logically, programs that are loaded often are prefetched more than programs that are not.

The prefetch files are located in %windir%\prefetch. That's C:\windows\prefetch for those who don't know. If you opened it now you would see a whole bunch of .pf files and one layout.ini file. All the .pf files are individual records of each program. The layout.ini file is a consolidation of all those programs and what they typically access, in order of priority.

The prefetcher requires scheduled tasks to work. If you have the service disabled or off, the prefetcher will not function.

?

?Windows XP Prefetching by default is already optimized. There are no tweaks that do anything but hurt performance. Anyone making any claims otherwise does not understand how Windows Prefetching works. They also do not provide documented and accurate reproducible testing to prove that some "tweak" does work. This nonsense has been copied off one site to another.

?It is completely impossible for unused entries in the Prefetch folder to slow a system down. Prefetch

files are trace files that simply include a list of files and their locations that are used by an application when it loads. Nothing is preloaded or cached in memory before you attempt to load an application.