Windows System

I know I had the Old Prefetch Data listed in the past, but all of a sudden I noticed that it's no longer there. What happened and how can I get it back? I have the 1.36 version.

I do appreciate your little program - thank you so much. It makes life a lot easier.

I know I had the Old Prefetch Data listed in the past, but all of a sudden I noticed that it's no longer there. What happened and how can I get it back? I have the 1.36 version.

I do appreciate your little program - thank you so much. It makes life a lot easier.

Its in the advanced section now due to general concensus being that cleaning the prefetch folder is a waste of time and harms performance.

Its in the advanced section now due to general concensus being that cleaning the prefetch folder is a waste of time and harms performance.

Thank you for your prompt response JD, however, it's not in the Advanced Section anymore, or anywhere else. That's why I sent this query. Also, when you say it harms performance, what do you mean by that? Do you no longer recommend deletion?

Thank you for your prompt response JD, however, it's not in the Advanced Section anymore, or anywhere else. That's why I sent this query. Also, when you say it harms performance, what do you mean by that? Do you no longer recommend deletion?

Not sure why its not there anymore, should be :blink:

I wouldn't recommend cleaning it. For a start programs will take slightly longer to launch and the prefetch folder regulates its own size anyway - once it gets to a certain number of entries it automatically deletes the oldest. As a result it never gets above about 5Mb.

This from the infamous XP Myths page (Link):

Every time you delete an application's Prefetch (.PF) file you will cripple that application's load time the next time you go to launch it. This can temporarily increase load times by as much as 100%. For one thing, XP will just re-create the Prefetch (.PF) trace files anyway; secondly, it trims the files if there's ever more than 128 of them so that it doesn't needlessly consume space. However you do not regain optimal application load times back until after the second time you launch the same application due to the Prefetch (.PF) trace file being re-created. Prefetch (.PF) trace files are not a cache and are not preloaded into memory upon windows startup. They are never even accessed until you launch an application. Only one Prefetch (.PF) trace file per application is created. There is never ANY reason to delete these files. Cleaning the Prefetch folder is actually a temporary self-inflicted unoptimization.

After reading this thread, I noticed that I no longer have the prefetch option either. :unsure: (FYI I'm running Win2k SP4)

Just make sure you are not looking in the advanced section of "options."

It is now in the advanced section at the bottom of the windows tab.

As for the prefetch option, it's all to do with personal choice, I have mine ticked with no ill effects. :)

If you are unsure what your Prefetch settings are or want to change them easily.

Download this: http://www.majorgeeks.com/download.php?det=2495

I definitely do not have the prefetch option under ANY subgroup in the CCleaner settings panel.

The program above appears to be for XP only, and since I have 2000, I've decided to give THIS program a try.

Is it normal for an OS to completely disable prefetching the way mine apparently has?

After some research, I believe that this prefetching function is only included with Windows XP and newer, which may be why I see no option for it in CCleaner on my Windows 2000 machine. If anyone has any more info on this subject please comment as I am still somewhat in the dark on this.

After some research, I believe that this prefetching function is only included with Windows XP and newer, which may be why I see no option for it in CCleaner on my Windows 2000 machine. If anyone has any more info on this subject please comment as I am still somewhat in the dark on this.

Hi TeeJay,

I have Windows XP and I did have Prefetch in the Advanced Option but it disappeared recently. However, this maybe far out, but I started thinking that the reason it's no longer there is because I have nothing saved in Windows Explorer under prefetch because I was always cleaning it. Does that make sense? After reading the forum about not recommending deleting the prefetch, then I guess I won't worry about it. But it makes me wonder why CCleaner put it there in the first place to give us the option to clean.

You may be able to get your Prefetch folder to working again by using this via Start, Run:

%windir%\system32\Rundll32.exe advapi32.dll,ProcessIdleTasks

Windows XP was the first version to have Prefetch.

Windows ME had a disastrous precursor called Applog.

I don't know if Vista has it.

EDIT: To change Prefetch parameters in XP:

HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ Session Manager \ Memory Management \ PrefetchParameters \ EnablePrefetcher

- create a new value of type DWORD if EnablePrefetcher doesn't exist

- set Data value [0 = Disabled, 1 = Application Launch Prefetch, 2 = Boot Prefetch, 3 = Prefetch All]

I have CCleaner ver 1.36.430 in "windows" tab "advanced" sub headder "Old Prefetch Data" is still there and I am using a P4 WinXP Pro (latest patches) aswell.

tried re-installing?

I have CCleaner ver 1.36.430 in "windows" tab "advanced" sub headder "Old Prefetch Data" is still there and I am using a P4 WinXP Pro (latest patches) aswell.

tried re-installing?

If your question is directed at Elkay, I think we're all agreed he should have "Old Prefetch Data" exactly where you say but if it's not there, the absence of the "detect" registry key HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\OptimalLayout must be the issue.

:D Thank you all for your support regarding my "prefetch" problem. I followed all of your suggestions and nothing seemed to work because my registry value was correct so I couldn't correct anything there. However, Glenn mentioned the "optimal layout" in the registry and I started looking in Registry Mechanic to see if I can relate that with something which may have been deleted. I did find it and used a restore of the optimal layout registry and lo and behold it's back!!! I did all that without knowing what I was doing. Guess I need to learn more about Registry Mechanic (or CCleaner?) and not be so enthusiastic about cleaning my PC all the time. Thanks again.