Prefetch

[fuzzy]

Could someone explain exactly what these "prefetch"
folders/files are and can they be safely deleted. The
files I am viewing end with EXE, TMP, SCR or NTOSBOOT.
Any help is greatly appreciated. I am Running XP and was
advised in a different forum pertaining to some other
software that these files should be deleted. Thank you.

 

[MAP]

-----Original Message-----
Could someone explain exactly what these "prefetch"
folders/files are and can they be safely deleted. The
files I am viewing end with EXE, TMP, SCR or NTOSBOOT.
Any help is greatly appreciated. I am Running XP and was
advised in a different forum pertaining to some other
software that these files should be deleted. Thank you.
.
Windows XP knows what programs you open most frequently

and place's these in the prefetch folder so when you
access them they open faster.Hence the name prefetch
Advice is to leave this folder alone.

 

[fuzzy]

Thank you MAP for your advise - I will take it - have a
great day.

 

[Paul J. Hurley]

I've been told by an "expert" that it's a "good idea" to delete the files
in your prefetch folder every few months. Take that for what it's worth.

Paul

 

[R. McCarty]

Prefetch essentially is a Boot/Application start time enhancer.
The process monitors both the Boot sequence and every application
start. It creates a .PF (Prefetch File) that contains data on what code
is loaded and where on the disk the code is found. At a fixed interval
these .pf files are collated into a module called Layout.Ini. Defrag then
takes Layout.Ini and defrags, placing the code in contiguous areas of
the disk drive. In layman's terms it essentially packs all the key code
modules into a disk area where it can be loaded very quickly. As far
as Boot time goes the benefit comes from "Parallel" loading. In earlier
versions of Windows it would load one driver or service then the next.
In XP, because of the layout, multiple drivers/services & apps can be
started simultaneously. This can viewed by using BootVis to see what
activities happen during boot and the sequence and time duration of
each.
Windows constantly monitors and updates the files inside of the folder
C:\Windows\Prefetch. If you count the .PF files in prefetch and recheck
perhaps a week later you will notice a change in the count. Many sites
recommend purging out the Prefetch folder. It doesn't harm anything,
but Windows will have to recreate and start over with the monitoring
and placement process.
Prefetch has four operational modes in a Dword Registry Key
"Enable Prefetcher"
0 = Disabled
1 = Boot Prefetch Only
2 = Application Prefetch Only
3 = Both Boot and Application Prefetch (Default).

 

[MAP]

Hi Paul,It may be true about deleting items in this
folder, don't know but I do know that I brought this
computer 2years and 2 months ago to date I've have no
problem.No repair install no reinstall I just turn it on
and go.

 

[fuzzy]

Thank you R. McCarty for your explanation - I understand
now what these are all about. Your help is greatly
appreciated. Have a great day.

 

[Alex Nichol]

Could someone explain exactly what these "prefetch"
folders/files are and can they be safely deleted.

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 , it is *not* necessary to empty prefetch.
Any program that does
not get used for a week 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.