Old Prefetch data

CCleaner for Windows
1

Hey guy's

Today I noticed that CCleaner wasn't removing (Old Prefetch data)

After clicking "Analyze" some prefetch data files were listed & ready to be deleted.

After clicking "Run Cleaner" the prefetch files are not in the list anymore, however under "Cleaning Complete" it says>(0 bytes removed)

If I click "Analyze" again, the same prefetch files are listed again? and the list of prefetch data files seems to be growing after I use CCleaner?

I've never had any problems with cleaning (Old Prefetch data)

This problem started for me with version: 2.12

I have the latest version: 2.13 and still have the same problem :(

2

The Old Prefetch data removal issue has been discussed:

http://forum.piriform.com/index.php?showtopic=17155

I do not have it checked in Advanced section and Windows manages it quite well.

3

Kenny I thing Craig is talking about a problem with CCleaner's ability to remove those files.

Not if they should be removed.

4

Have you checked how old the prefetch files are craig? (Right click\Properties).

CCleaner deletes prefetch files older than 14 days. You can collect a lot of files in 14 days.

Just a thought. :)

5
Have you checked how old the prefetch files are craig? (Right click\Properties).

CCleaner deletes prefetch files older than 14 days. You can collect a lot of files in 14 days.

Just a thought. :)

Hi Dennis ;)

Yes the files in question are older than 14 days.

Some of these files relate to programs that I haven't used for months?

As I mentioned in my "1st post" CCleaner has never had any problems deleting old prefetch data files :huh:

I'm wondering why it cant remove them now?

Maybe Windows has decided to rebuild it's prefetch data list' and is not allowing it's list to be cleaned?

Could all this have something to do with a Windows update?

6

I've no idea craig, and I can't test my version of CCleaner as I only re-enabled my prefetch folder a few days ago.

7

14 days old ???

I have 116 Prefetch files.

Their CREATED dates range from 19/08/2008 to 08/11/2008

Their MODIFIED dates range from 24/10/2008 to 08/11/2008

Their ACCESSED dates are all 08/11/2008.

Which of the three possible date types in Windows Explorer is craigathus looking at when he says some are more than 14 days old ?

Which of these three date types does CCleaner use when deciding if a file is more than 14 days ?

Are we comparing apples with oranges ?

Regards

Alan

8

A slight modification to my previous post. It's amazing how something can read differently the second time you read it.

Old Prefetch Data

In Windows XP a Prefetch file is generated each time an application is run. This helps Windows optimize the application the next time it is executed. Unfortunately these files are not deleted when the applications are removed. This option removes these files for programs that haven't been accessed in 14 days. (This process is very safe and Windows will recreate the files as necessary.)

This is from the CCleaner Beginners Guide, which it appears few here have read. I read it wrong, but at least I read it. :rolleyes:

Would the guilty parties please raise their hands?

9

Would the guilty parties please raise their hands?
I could not find a raising hand smiley though :lol:
10
A slight modification to my previous post. It's amazing how something can read differently the second time you read it.

This is from the CCleaner Beginners Guide, which it appears few here have read. I read it wrong, but at least I read it. :rolleyes:

Would the guilty parties please raise their hands?

Hey Dennis ;)

I've read it! "CCleaner Beginners Guide" and I even have a "shortcut" to it on my desktop :lol:

OK I've been using CCleaner for a while now, and basically what I'm saying is that for some reason these files are not being "deleted" anymore?

However they were being "deleted" before.

Version 2.12 was doing it's job... finding and deleting "old prefetch data"... then for some reason? it started listing these files for "deletion" but not deleting them?

Version 2.13 is finding "old prefetch data" and marking these files for "deletion" but not deleting them :huh:

Quote>Alan_B

Which of the three possible date types in Windows Explorer is craigathus looking at when he says some are more than 14 days old ?

When looking at a files "Properties" I look at the (Created & Modified) dates.

Please correct me if I'm wrong... I thought the (Accessed dates) and the (Modified dates) were usally going to be the same?

Answer to the question> the latest date.

The bottem line is... I've decide to let Windows manage it's "Prefetch data files" and have unchecked (Old Prefetch data) option in CCleaner.

11
When looking at a files "Properties" I look at the (Created & Modified) dates.

Please correct me if I'm wrong... I thought the (Accessed dates) and the (Modified dates) were usally going to be the same?

Answer to the question> the latest date.

Hi

In principle the original idea was, or should have been, that :-

Created is when the file was first created;

Accessed is the last time anything read the contents;

Modified is the last time the file was re-written.

All three dates should exactly match at the instant when the file first appears.

In practice that may happen sometimes - but not so much now we have Windows !!!

Using Xplorer2, a dual pane alternative to Windows Explorer, and also DIR in a DOS CMD Shell, I captured :-

Name                     Modified              Created               AccessedNew_Files.rtf            22/07/2007 21:17:14   23/05/2007 17:45:18   09/11/2008 15:41:40TweakMASTER-Install.exe  23/05/2007 16:17:34   23/05/2007 16:17:24   09/11/2008 15:36:08C:\Documents and Settings\Dad\My Documents\My Received Files\Edit_etc>DIR /T:A09/11/2008  15:41               577 New_Files.rtf09/11/2008  15:36         1,728,160 TweakMASTER-Install.exeC:\Documents and Settings\Dad\My Documents\My Received Files\Edit_etc>DIR /T:A09/11/2008  15:41               577 New_Files.rtf10/11/2008  14:08         1,728,160 TweakMASTER-Install.exe

It is worth noting that the Tweak*.exe file was "opened" when the download started,

and 10 seconds later the download ended and my Anti-virus scrutinised and permitted the contents on-board,

hence the 10 second delay after "Created" before "Modified".

*.exe files can damage Windows (e.g. a virus) so Windows gets its retaliation in first, and the Accessed date gets caught in the cross-fire !!!

Another possibility is simply that System Restore inspects many file types, including *.exe but excluding *.rtf, with a view to capturing copies in a restore point incase the get changed.

Either way, and in addition, if Windows ever sees a file in a directory listing, it instantly trashes the Accessed date to "NOW".

Furthermore, if the file is an *.exe :-

the new date is instantly put in whatever DOS "DIR" reads (I guess I mean the disk, but Windows has so many peculiarities I am not sure);

otherwise the new date is held pending, and written to the disc (or whatever) upon close down ready for the next time the computer starts up.

Before I used Windows to show all three dates of two files, I captured the first of the two DIR lists, hence the Windows list and the first DIR list show the same Accessed date.

I then captured the second DIR list, which shows that Tweak*.exe has just been "Accessed". Windows does not show this change other than in a new instance of Windows Explorer etc.

The New*.rtf Accessed date is also punished - but it is suspended and pending via a different mechanism.

Even launching a new instance of CMD still shows the old accessed date, BUT it is going to change.

The first of the two DIR lists proves the New*.rtf will get punished.

Yesterday at 09/11/2008 15:36:08 I performed the same operations as today, after which the New*.rtf date remained as per Modified, i.e. 22/07/2007 21:17:14.

Today New*.rtf date had become 09/11/2008 15:41:40, which is 5 minutes after 09/11/2008 15:36:08 and corresponds to when I closed down the computer.

Files with alternative extensions may suffer alternative consequences.

The above tests were done within my private documents, from which System Restore is excluded.

If you are looking at C:\Program Files\* the waters become muddy !!!

Finally, Modified should be later than Created, but not always, as an example :-

C:\WINDOWS\system32\c_20127.nls :- Modified 18/08/2001 19:00:00; Created 20/05/2003 16:24:58.

My guess is the source code was last changed in 2001, but a security hole was found and, with no change to the raw source code, conditional compiler directives or something may have altered the EFFECT of the code (e.g. specifying a different or updated library) and a new c_20127.nls was created and transferred on a Patch Tuesday Update. 20/05/2003 16:24:58 may be the date of Patch Tuesday hitting this particular computer, or when the latest version was prepared for release to every-one, or .......

Conclusions :-

1. The Accessed date is extremely vulnerable to damage if Windows should look at the file;

2. The other two dates often mean what they say - but there are exceptions to this general rule;

3. When in Windows, tread carefully !!!

n.b. Some of the above I learnt today - Windows is a never ending bag of tricks.

Regards

Alan

12
I've decide to let Windows manage it's "Prefetch data files" and have unchecked (Old Prefetch data) option in CCleaner.

That's what I've been using myself for ages, since Windows itself will deal with them.

One way to possibly get rid of outdated Prefetch data is if you're using WinXP is to start Dial-a-fix and in Dial-a-fix do the following:

1. Click the Tools icon.

2. In Tools click Process Idle Tasks.

13
One way to possibly get rid of outdated Prefetch data is if you're using WinXP is to start Dial-a-fix and in Dial-a-fix do the following:

1. Click the Tools icon.

2. In Tools click Process Idle Tasks.

Or simply click Start>Run and enter the command (rather than download a program to do it):

rundll32.exe advapi32.dll,ProcessIdleTasks