What is Prefetching in Windows?

Prefetching is a technology in Windows that speeds up the launch of applications. Here’s how it works:

When you frequently open an application (e.g., a browser or text editor), Windows takes note and prepares everything in advance. It remembers which files and data are needed for the launch and preloads them into RAM
The next time you open the application, the necessary files are already ready.
If the application is updated or you launch it for the first time, Windows automatically creates new instructions for a faster start.
Windows stores this data in Prefetch folder. It’s better not to delete its contents—this could slow down application launches.

This technology does not affect the overall speed of the computer, only the launch of applications.

Should you disable prefetch in Windows?

Prefetching is a smart aid for the system, and in most cases, it’s not necessary to disable it:

Reduced application launch speed.
Disabling it may cause applications to take longer to load – especially noticeable on weaker computers.
Minimal impact on resources.
Prefetch does not burden the system in the background.
Benefits outweigh the risks.

How to disable Prefetch (if absolutely necessary):

Press Win + R, type regedit, and open the Registry Editor.
Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters
Find the EnablePrefetcher parameter, double-click it.
Change the value to 0 to disable Prefetch.
Restart your computer.

The MaxOperationAPIFiles parameter

MaxOperationAPIFiles is a setting that determines how many file operations Windows can handle in parallel during prefetching. A higher value allows the system to precache more data in advance.

Default value:

Windows 10 and older versions: 256.
Windows 11: 512.

Is it worth increasing the value?

Increasing the parameter to 1024 or even 2048 could improve Prefetch performance in scenarios with very intensive multitasking (e.g., launching dozens of “heavy” applications simultaneously). However:

The effect is hard to notice. The difference in application launch speed will be minimal or unnoticeable, especially on modern SSDs.
There’s no guarantee of results. Windows already manages resources efficiently, and increasing the value is more of an experiment than a solution to a real problem.
Measuring the improvement is nearly impossible. Special tools like system boot analyzers or benchmarks are required, which are unavailable to most users.

Checking the current value:

Open Terminal (Administrator)
Run the command Get-MMagent
Run the command (Get-ChildItem “C:\Windows\Prefetch\*.pf” -File).Count

Changing the Value:

Open Terminal (Administrator)
Enter the command to set a new value: Set-MMAgent –MaxOperationAPIFiles 1024

Restart your computer.

Note

Values above 2048 may create unnecessary disk and memory load without any benefit.
Revert to default settings if you notice slowdowns or errors:

For Windows 10: Set-MMAgent -MaxOperationAPIFiles 256

For Windows 11: Set-MMAgent -MaxOperationAPIFiles 512

Create a system restore point before making changes.