Prefetch

[JOHN A.]

Can someone tell me what a Prefetch (pf) file is, and can it be deleted
safely

Thanks in advance

 

[Chris Lanier]

Check out... http://www.majorgeeks.com/download.php?det=2495

 

[Wesley VogelX]

JOHN;
Windows XP monitors the files that are used when the computer starts and
when you start applications. By monitoring these files, Windows XP can prefetch
them. Prefetching data is the process whereby data that is expected to be
requested is read ahead into the cache. Prefetching boot files and applications
decreases the time needed to start Windows XP and start applications. This
information is logged and stored on your hard drive taking up space and
requiring a process to be kept running monitoring which applications are being
run.
Add C:\Windows\Prefetch to the list of directories to empty periodically.
This folder is probably full of prefetch directions for applications you no
longer use. You can safely remove these files; any files that are needed will
be created again automatically. Don't delete the folder, just the contents.
Hope this helps. Let us know.
Wes

 

[Alex Nichol]

Can someone tell me what a Prefetch (pf) file is, and can it be deleted
safely

When a program is loaded, a record is put, or updated, in the
corresponding file in Prefetch, detailing what files it uses, in what
order. Boot of the system has such a record, too

From that two things happen.

One - when a load is started in future, the system arranges to get the
expected files into RAM straight away, without waiting to be asked, and

Two - every three days, a sort of semi-defrag run is done in a quiet
period, which arranges files so that such sets will be able to load as a
smooth stream without need to hunt around the disk for them. The boot
side of this speeds load of the system: the Bootvis program does a
preliminary optimisation of their layout, but it will take place, and
better, through the automatic process. The details of the best layout
are kept in the layout,inf file which is checked and updated each time
this optimisation runs, for the best overall performance. This can be
used for optimisation alternatively by some third party defrag programs,
eg Perfect Disk Pro

Two points:

Contrary to what is said (most recently I notice in Fred Langa's Langa
list), it is *not* necessary to empty prefetch. Any program that does
not get used for a while will have its file dropped out anyway: ones
that are rarely used get low priority in optimisation

and:
The optimisation at regular intervals is initiated by task scheduler so
you need to have it running for this to work (also for System Restore
to make its daily restore point) even though no scheduled task appears
if you look in control Panel - Scheduled tasks. Check the Advanced menu
there, and if it says 'Start Using. . ' click that so it says 'Stop
using . . .' It then looks for a time when the system is quiescent (I
think it waits for 15 mins of no disk activity, but am not sure on
that). This is one reason for the query 'my hard disk goes chattering
when I am doing nothing'; the other being search engine indexing.

 

[Wesley VogelX]

Alex;
I have been emptying (deleting) my prefetch file quite often. I have taken note of
your mention that this not being necessary. I will monitor it for a while and see what
takes place.
This may not be related at all. In my Add/Remove Programs, programs that are used
every day are listed as being used rarely or occasionally. Curious.
Wes

 

[Alex Nichol]

This may not be related at all. In my Add/Remove Programs, programs that are used
every day are listed as being used rarely or occasionally. Curious.

Certainly not related to Prefetch - what criteria Add/Remove takes are
not clear. Nor the ones used in deciding which 'recently used' programs
should appear on the left of the Start Menu. Most are OK, but I find
'Debug' keeps reappearing, though I never use it

 

[Wesley VogelX]

Alex;
Ah, the foibles of XP.
Wes

Certainly not related to Prefetch - what criteria Add/Remove takes are
not clear. Nor the ones used in deciding which 'recently used'
programs should appear on the left of the Start Menu. Most are OK,
but I find 'Debug' keeps reappearing, though I never use it