Flush the Windows XP Prefetch log!

[FreewheelinFrank]

The only reference I can see to Prefetch files being deleted is this:

For one thing, XP will just re-create that data anyways; secondly, it trims the files anyways if there's ever more than 128 of them so that it doesn't needlessly consume space.

http://blogs.msdn.com/ryanmy/archive/2005/05/25/421882.aspx

[Lisandro]

The article however does poin't out that the prefetch log should NOT be deleted or cleaned out.

I fully agree with this... I just want to know the other point.
Discussing if Windows XP Prefetch folder should be flushed or not is useless... you should not clean it.
What I can't understand is why CCleaner, for instance, still have this option there 

[FreewheelinFrank]

I just want to know the other point.

According to the MS man, the number of Prefetch files will not be allowed to go over 128. I assume Windows will delete the least used, but that's just a guess.

[FreewheelinFrank]

What I can't understand is why CCleaner, for instance, still have this option there

The reason I heard on the CCleaner forum is that you might want to remove all traces of a program you installed. Somebody put it more bluntly on Warp2Search:

Commentary misses the point with knee-jerk reaction. The prefetch cleaning option is not intended to increase performance but simply remove a run history of applications. Users may not want it recorded that they ever ran pr0nmaster5000.exe or continue to do so from a removeable flash drive.

http://www.warp2search.net/modules.php?name=News&file=article&thold=-1&mode=flat&order=0&sid=25820

Of course, as CCleaner only removes Prefetch files over two weeks old, this is not exactly going to work as a privacy clean up tool. 

[Mastertech]

Hi malware fighters,

Cleaning up the Win XP Prefetch file can be advisable for better performance, and freeing some space on your HD. There is a special tool to do this:
http://www.majorgeeks.com/download2495.html

Tool for flushing the Prefetch log and controlling the Prefetch Parameters.

Prefetch is available to load websites faster.

polonus

God why does this Myth never die? The Windows XP Prefetcher has nothing to do with loading websites faster. You are confusing Browser Prefetching such as Fasterfox with Windows XP Prefetching. Windows XP Prefetching is already configured optimally by default and should never be cleaned or disabled. Unless of course you want Windows and all of your applications to load SLOWER! Prefetching simply optimizes how applications and Windows XP loads.

Anyone who recommends cleaning the folder, disabling the Windows XP Prefetching or "tweaking" it in ANY way has absolutely NO idea how it works.

http://mywebpages.comcast.net/SupportCD/XPMyths.html

[Mastertech]

Flushing the Prefetch log could initially have a detrimental effect as it will take at least three boots to rebuild the layout.ini file.

If you are concerned about the size of the prefetch folder, you can restrict the files that it monitors, mine is set to only monitor files that run on boot. Currently my prefetch folder is a huge 0.97MB so no space overhead at all.

Concerned? The folder never gets over 128 entries in it which averages around 5MB. It is self cleaning at 128 entries. Disabling application prefetching will slow down how long ALL you applications take to load! You should NEVER do this unless you want your applications to load slower. Anyone who is concerned about the ridiculously little disk space this takes up does not understand Windows XP Prefetching.

[Mastertech]

The only time that I would clear prefetch is after a serious malware infection.  More as a tidying up exercise than anything else, so that anti-spy tools don't latch onto the old files and give the misleading impression of malware still active

Nope that is another Myth. Prefetch files are non executable. If a file is an actual malware file (rare) and is located in the prefetch folder, it will have a different extension other than .pf and you should just delete that file NOT the whole contents of the Prefetch folder. Do you delete the Windows folder if you find an infected file? Nope.

[Mastertech]

Hi, I use ccleaner like so many people do,and it cleans 'old prefetch data' by default.I've never noticed any problems using this.So is it adviseable to uncheck this option in ccleaner?

Bad idea, this will reduce performance since it cleans the Prefetch folder's files based on the NTFS last access date for each when they are two weeks old. This is idiotic for a number of reasons, first the folder is self cleaning by Windows XP when it reaches 128 entries and outdated or unused prefetch files in NO WAY negatively effect performance ever. Even worse is if you have the NTFS last access date turned off this will clean the whole folder! Never select this option and it is FINALLY disabled by default in the latest version of CCleaner but should be removed completely. The makers of CCleaner have no concept of how the Windows XP prefetcher works.

CCleaner Cripples Application Load Times

[Mastertech]

And even here i think Windows clean old stuff automatically anyway...

Are you sure...? I think the entries of the prefetch folder stay there forever..., even programs that no long exist anymore 

Nope it is automatically cleaned at 128 entries.

[Mastertech]

I'll have to believe, although I can't understand how it's being done...

Windows assigns a value to all prefetch files and only the most used (important) 32 are kept once the 128 limit is reached.

[Mastertech]

What I can't understand is why CCleaner, for instance, still have this option there 

Because the maker of CCleaner has no concept of how Windows Prefetching works. If he spent five minutes talking to a member of the Windows Client Performance team he would know. It only proved his ignorance when he started locking and deleting all topics about it in his forum, only to wait almost ten months to remove it from the default because the evidence was undeniable.

I am surprised Frank did not reference my extensive XP Myths site on this issue which covers it in depth.

[polonus]

Hi Mastertech,

But how about pre-fetch and the elimination of evidence. You won't stand a chance with the secret life inside Windows, and what goes on the general public is not aware of.
But could not it be that the contents of the PreFetch folder could give you away, if educated people (forensics)  would like to search the contents of your computer. Would you stand a chance? To-day with all the external content retaining even your airbag blackbox data can land you in jail for life, elimination of certain data could be vital to your well being, leaving the pre-fetch folder on or the way "delete" works with Windows makes it a dangerous machine. I have nothing to hide, but those that had should stay miles away from any technical apps (computer, printer, cell phone, etc).
Is there ueberhaupt a way to use Windows sothat your privacy is guaranteed?

polonus

[Mastertech]

What could someone get from your Prefetch information? That you ran the programs you have installed on your PC? I think the personal information in your My Documents folder would be of more interest.

Unless you routinuely run a US DOD level wipe of deleted files then they can find quite a bit out.