Every time you run an application in your PC, a Prefetch file that contains information about the files loaded by the application is created by Windows operating system. The information in the Prefetch file is used for optimizing the loading time of the application in the next time that you run it.
What is a Prefetch Folder
Windows uses this directory to speed up launching applications. It analyzes the files you use during startup and the applications you launch, and it creates an index to where those files and applications are located on your hard disk. Using this index, Windows can launch files and applications faster.
How to view Prefetch Files
WinPrefetchView is a small portable freeware utility that reads the Prefetch (.pf) files stored in your system and display the information stored in them. It is available here.
By looking in these files, you can learn which files every application is using, and which files are loaded on Windows boot.
This utility works on any version of Windows, from Windows XP to Windows 10. Earlier versions of Windows are irrelevant for this utility because they don’t use Prefetch files.
If, when you run the app you cannot see any files in your prefetcher, you may have to take ownership of your C:\Windows\Prefetch folder. You may use UWT to do so easily via the right-click context menu.
Tweak Prefetch Files
TweakPrefetch is an easy to use application that is designed to manage your system’s fetching. It allows the user to set separate parameters for Prefetch and Superfetch. It is available here.
If you notice that Windows won’t rebuild the “Layout.ini” file after you have cleaned the Prefetch folder, or maybe you just want to update it to your latest startup configuration, you can force the process using the “Rebuild Layout.ini” function in the “Options” menu.
TweakPrefetch will also detect wrong parameters for Prefetch and Superfetch and will let the user fix them with a single click. Version 3.0, implements a fetching configuration wizard, which will help less experienced users to find the optimal Prefetch and Superfetch settings for their system and needs.
For the regular Windows user, however, the Prefetcher is best left alone!
Some utilities have an option to clear the prefetcher. Should you choose to use this option of ‘clearing prefetcher‘, be ready to run an ‘un-optimized’ windows for a little while. As mentioned earlier, the Prefetcher is best left alone! In any case, Windows cleans it at 128 entries down to the 32 most used application’s prefetch files.