# Old Prefetch Data



## raybro (Apr 27, 2003)

Just continuing to work at understanding the various aspects of the Cleaner Tool feature in CCleaner

Can someone explain just what "Prefetch Data" is. I know it's something to do with RAM, but I'm unsure of the details. I looked it up in Wikipedia, but that was not real helpful. What I'm most interested in is, what would be the net effect (up side/down side) of 'Cleaning' old prefetch data.

Raybro


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## Rich-M (May 3, 2006)

Prefetch is a Windows folder that contains shortcuts to certain programs used frequently to aid in their quicker startup. Emptying that folder is not harmful, in fact it is a common thing to do in removing malware. Whatever you do do not use the reg cleaner in ccleaner. It can and has hosed a few systems I was working on in the past before I knew it was there.


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## TOGG (Apr 2, 2002)

Googling 'prefetch data' will produce hits that confidently assert that deleting prefetch data is good, bad, useless or anything in between.

At first glance it does appear to be just another example of pointless Microsoft bloat and I have been tempted to let CCleaner remove it. On the other hand, there is the golden rule 'if it ain't broke, don't fix it'.

See what you make of this thread from Piriform's Forum; http://forum.piriform.com/index.php?showtopic=22693


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## raybro (Apr 27, 2003)

TOGG said:


> See what you make of this thread from Piriform's Forum; http://forum.piriform.com/index.php?showtopic=22693


Well, if nothing else, that post gives me a much better idea about just what prefetch is and does. I can understand now (at least theoretically) how going through and periodic cleanout of the shortcuts stored in the prefetch folder could initially slow down the overall system, but speed it up in the longer term.

Having said that, I took a look into the prefetch folder and found it contains some 78 items. I didn't see any that did not represent currently used programs. Running CCleaner with the "Old Prefetch Data" box checked comes up with zero items as candidates for cleaning. According to the Piriform post, that means none represent old (whatever that means) or nonexistent (removed) programs. I don't completely buy this because I have removed a couple of programs in the last few days and there are no items representing them.

My conclusion is the whole question is a nit and I don't think I'll waste any more time on it. I doubt it makes any significant difference either way.

I'll mark the thread "Solved"

Raybro


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## Noyb (May 25, 2005)

Ive run prefetch Enabled and Disabled ... And I can't tell any difference.
CCleaner cleans out out anything older than two weeks ... (as I remember).

This sounds like a good comprise between all or none ... 
So I have CCleaner checked to clean the prefetch.


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## Rich-M (May 3, 2006)

Me too I wrote a batch file in 2 pc's to empty the Prefetch every bootup and I never saw any difference.


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## Noyb (May 25, 2005)

You don't need to write a batch file ...
http://majorgeeks.com/Windows_XP_Prefetch_Clean_And_Control_d2495.html


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## Kenny94 (Dec 16, 2004)

IMO.. There's no difference I can see.


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## Noyb (May 25, 2005)

I'm thinking there may have been some advantage on the old/slow computers that were around when XP was introduced ...
But not nowadays.


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## Rich-M (May 3, 2006)

Noyb said:


> I'm thinking there may have been some advantage on the old/slow computers that were around when XP was introduced ...
> But not nowadays.


You are probably right on that thought.


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