What are prefetch files? Prefetch directory: what is this folder and why is it needed?
It’s difficult to follow developments without being an expert operating system Windows. But there are basic concepts that every user should understand. Knowing which folders are responsible for what in Windows will make it easier to navigate the system. An example of files unknown to us is the contents of C:/Windows/Prefetch.
Purpose of the folder
Let's answer the question: why do we need the Prefetch folder? When Windows starts, it analyzes programs that we often use (we open them ourselves or using startup). The system then creates information about these programs, which it stores in special temporary files in the Prefetch folder. Subsequently turning on Windows these files speed up loading of the OS.
The OS component is responsible for performing this work. If you remove them, no changes will occur. The next time you start it, Windows will again collect current data about programs and place it in the Prefetch folder. However, loading the OS may take a little longer than usual.
Prefetch was first used in Windows XP. With the advent Windows Vista the folder was supplemented with SuperFetch technologies (responsible for analyzing frequently launched applications) and ReadyBoost (responsible for increasing performance). You can find it in this path: C:/Windows/Prefetch.
Managing the Prefetcher Service
You can control the operation of the Prefetcher service in the registry editor:
This parameter operates with values from 0 to 3, which mean:
- 0x00000000 - disabling the component;
- 0x00000001 - acceleration of application loading;
- 0x00000002 - acceleration Windows startup;
- 0x00000003 - acceleration of OS and application loading.
The default value is 3. To disable the service, enter the value 0 and restart the PC.
Important! The developers made sure that the Prefetch folder did not accumulate files (and gigabytes of disk space), creating a limit of 128 trace files.
Answers on questions
Is it possible to delete the Prefetch folder and the data it stores?
No. This doesn't make sense for three reasons: 
It is difficult, without being an expert, to keep track of the development of the Windows operating system. But there are basic concepts that every user must understand. Knowing which folders are responsible for what in Windows will make it easier to navigate the system. An example of files unknown to us is the contents of C:/Windows/Prefetch.
Purpose of the folder
Let's answer the question: why do we need the Prefetch folder? When Windows starts, it analyzes programs that we often use (we open them ourselves or using startup). The system then creates information about these programs, which it stores in special temporary files in the Prefetch folder. The next time you turn on Windows, these files speed up the loading of the OS.
The OS component is responsible for performing this work. If you remove them, no changes will occur. The next time you start it, Windows will again collect current data about programs and place it in the Prefetch folder. However, loading the OS may take a little longer than usual.
Prefetch was first used in Windows XP. WITH the advent of Windows The Vista folder was supplemented with SuperFetch technologies (responsible for analyzing frequently launched applications) and ReadyBoost (responsible for increasing performance). You can find it in this path: C:/Windows/Prefetch.
Managing the Prefetcher Service
You can control the operation of the Prefetcher service in the registry editor:
This parameter operates with values from 0 to 3, which mean:
- 0x00000000 - disabling the component;
- 0x00000001 - acceleration of application loading;
- 0x00000002 - Windows startup acceleration;
- 0x00000003 - acceleration of OS and application loading.
The default value is 3. To disable the service, enter the value 0 and restart the PC.
Important! The developers made sure that the Prefetch folder did not accumulate files (and gigabytes of disk space), creating a limit of 128 trace files.
Answers on questions
Is it possible to delete the Prefetch folder and the data it stores?
No. This doesn't make sense for three reasons:
Folder Prefetch can be found in Windows XP, Vista, 7, 8 at the following path: C:\Windows\Prefetch - it is a component of the operating system and speeds up the process bootstrap OS and frequently used programs. First this technology was used in Windows XP, and starting from Vista it was supplemented with SuperFetch and ReadyBoost technologies. Launching an OS or application is accompanied by reading data from memory; often the same file has to be accessed several times, which is very irrational and takes a lot of time. Windows optimizes code loading by storing trace files in the Prefetch folder, which it processes in its own way.
For settings Prefetch folders er we will need a registry editor. I would immediately like to duplicate the warning from the Microsoft website: " Misuse Registry Editor may cause serious problems that may require you to reinstall your operating system. You use the Registry Editor at your own risk."
Click Start - Run and enter regedit. In the Registry Editor we will find the following section: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters
We are interested in the parameter EnablePrefetcher. It can take the following values:
0x00000000 - component is disabled
0x00000001 - acceleration of application launch
0x00000002 - system boot acceleration
0x00000003 - acceleration of application launch and system boot
In the way that disable Prefetch you need to double click on the parameter EnablePrefetcher and in the dialog box specify the value 0 . The default is 3 - for more quick launch applications and Windows boot. The need to disable Prefetcher often arises when working with Windows 8 - many new laptops are not equipped with a traditional HDD hard drive, but an ultra-fast SSD drive, which are still characterized by high cost and small memory capacity.
When installed SSD drive Windows 8 should automatically disable the Prefetcher service, but if this does not happen, you can remove Prefetch yourself. In the above registry key for the settings EnablePrefetcher And EnableSuperfetch need to set value 0 , that is, turn them off. Restart your computer.
Windows system files and folders have many myths, and the service we are considering is no exception. We often hear questions: is it possible to delete the Prefetch folder, how to disable or enable Prefetch. But the most interesting misconception is that adding a key /prefetch:1 in the link to the object in the "shortcut" tab speeds up the loading of the application, since the OS, seeing given key, adds the program to the Prefetch folder. Adding /prefetch:1 to the address will do nothing, and the myth is based on the fact that a similar key is present in the startup line Windows Media Player.
People often ask, is it possible and necessary to delete files from the Prefetch folder? Supposedly, this allows you to free up space on your hard drive. The answer is clear: NO. Firstly, when these files are deleted, the loading time of the OS and some programs will increase, and the trace files will be created anew. Secondly, Prefetcher itself manages these files without the need for third-party intervention. In addition, Microsoft limited the number of trace files to 128 pieces so that they do not take up too much disk space.
Now about one more useful function, her name is Prefetch.
This feature is designed to optimize the loading experience of the apps you download. So that they load faster the next time you boot.
If I remember it right.
It would seem, why should we touch her?
The fact is that over time, a lot of files from the applications that you launched accumulate in the Prefetch folder. And if, in addition, something was installed and deleted, then the files in Prefetch from remote programs remain. And this begins to slow down the system.
Because when the system boots, Windows tries to find all the files that are listed in Prefetch.
There is no clear opinion on what to do about this; some recommend deleting and emptying this folder at every boot, some clean it once a week; most users advise disabling it altogether.
But this function is certainly useful.
The only thing is to clean it if you have the ability to install and remove different programs maybe once every two weeks.
If you just use already installed programs, you can sometimes clear them when you remember. :)
These same files, or rather, their common denominator - the \Windows\Prefetch\layout.ini file - are then used by the defragmenter to optimize the location of files on the disk, which further reduces loading time.
If you're not yet confused, Prefetch is a built-in optimization function.
What is she doing?
This function is designed to reduce the loading time of applications, those that are loaded at system startup and those that you often use.
So Prefetch contains files from the most frequently downloaded programs, sometimes not from frequently downloaded ones. On what Windows principle I don’t know who selects them. Maybe whatever God puts on your soul.
And then windows waits until you leave your computer and go smoke, drink tea, etc. I don’t remember exactly after what time, in my opinion after 20 - 30 minutes of machine inactivity.
Windows, according to the data in the Prefetch folder, begins to shuffle programs that are often used to load faster to the beginning of the disk.
Just like I mentioned, it optimizes the loading of programs, in addition to moving them.
But often, when optimizing their system, users unwittingly disable this function.
The point is for normal operation This service needs three things that are often disabled. Or rather, two of them are turned off.
1. Built-in defragmenter
2. task scheduler
3. Doctor Watson (although I don’t remember exactly).
It is advisable to remember this.
So what else can we do?
1. Delete either all files from this folder or files from those programs that are no longer on the machine.
2. find HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters\
There's a key there EnablePrefetcher(REG_DWORD)
The values that apply to it are (0, 1, 2, 3)
0 – disabled (Recommended for low-power computers)
1 – recommended for computers with RAM up to 256MB (Programs only)
2 – For those who have 512MB or more on board (programs and system libraries)
3 – This is already designed for super-duper powerful processors + at least 512MB of RAM, although with LargeSystemCache=1 it works great on 256MB of RAM.
I recommend EnablePrefetcher=3
"Enable"="Y"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction
"OptimizeComplete"="Yes"
There is one legend walking around the Internet.
That in Windows Vista all applications will launch and run 15% faster than in Windows XP. So you don't have to wait at all Windows release Vista, in order to experience all the delights of this cartoon, because... they are already included in WinXP SP2!!! All that remains is to enable this cartoon (Super Prefetch). This cartoon works ONLY under Windows XP SP2!
HKEY_LOCAL_MACHINE\SYSTEM\ CurrentControlSet\Control\Session Manager\ Memory Management\PrefetchParameters\
1. Create a type parameter
DWORD
Value Name: EnableSuperfetch
Value: 1
2. Someone says that you need to create a separate section.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\
Create a section Prefetcher
Create a type parameter
DWORD
Value Name: EnableSuperfetch
Value: 1
Opinions are divided, there are comments about the myth of this parameter, there are those who have noticed an increase in productivity.
In any case, to check. You have nothing to lose and nothing to gain except extra entry in the registry.
P.S. If anyone has a beta version of Vista, please export the branch HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\Control\Session Manager\Memory Management
And send it to me if you don’t mind.