Which information can we recover from an hard disk.

[John70]

I've been told that if I delete a file from the disk or if I save a
newer version of a file eg Word Document, there are of getting both,
ie, recover the deleted file and also recover previous version of the
files I've saved (this example, the Word Document). Is it true?
Because I have sensible information that I had to remove from my
computer how can I prevent that without having to format and reinstall
Windows again?

TIA

 

[Shenan Stanley]

I've been told that if I delete a file from the disk or if I save a
newer version of a file eg Word Document, there are of getting both,
ie, recover the deleted file and also recover previous version of
the files I've saved (this example, the Word Document). Is it true?
Because I have sensible information that I had to remove from my
computer how can I prevent that without having to format and
reinstall Windows again?

I am unsure what you are asking...

Are you asking if you can recover a permanently deleted file (out of the
Recycle Bin) and also previous versions of that file?

If so - you *may* be able to recover a permanently deleted file using
various packages. However - for the most part you will not be getting
different versions of that file unless you planned ahead in some way.

I recommend a software package called, "UnDelete".

What is 'sensible information'?

 

[Jim]

I am unsure what you are asking...

Are you asking if you can recover a permanently deleted file (out of the
Recycle Bin) and also previous versions of that file?

If so - you *may* be able to recover a permanently deleted file using
various packages. However - for the most part you will not be getting
different versions of that file unless you planned ahead in some way.

I recommend a software package called, "UnDelete".

What is 'sensible information'?

I'll surmise that he meant "sensitive information".
What the OP wants is a program which performs a multpass overwrite of a
given file.
I wrote such a program a long time ago, but it was for an ODS-II volume on
Alpha VMS.
What the program did was chase through the disk for all of the extents of
the file, It filled the files with all bits clear, all bits set, and bits
set base on the results of a random number generator whose seed was the time
of day. It left the file header alone so that none of the supplied programs
could make any sense of the file.
I suppose one could write such a program for Windows, but that person will
not be me.
Jim

 

[Anteaus]

This is a complex question with no simple answer. Although, the lowdown is
Yes, deleted copies can be salvaged relatively easily, as only the
directory-entry is removed, the data remains on-disk until that space is
needed again.

Word is a particular problem in this respect, since it creates temporary
files whilst editing is in progress, and doesn't always delete them (even
from the disk directory)

There are utilities to securely erase files, but these are only effective if
they are USED to delete the file. If the file was deleted by other means they
may not help.

http://www.analogx.com/contents/download/system/shred.htm

Lowdown is, if you have sensitive data, e.g. payroll, then you would be
better to use a dedicated program, or else store the data in a Truecrypt
volume.

http://truecrypt.org

 

[John70]

I'd like to thank you for your information. Indeed I meant sensitive
information.

Since friday I've been thinking on this and I thought doing the
following:
- Delete the files I need to remove from disk
- Delete all temporary files including on local folders
- Proceed to defrag ( using Windows Defrag or even Contig from
Sysinternals )

Any opinion on this are appreciated.

TIA

 

[Bruce Chambers]

I'd like to thank you for your information. Indeed I meant sensitive
information.

Since friday I've been thinking on this and I thought doing the
following:
- Delete the files I need to remove from disk
- Delete all temporary files including on local folders
- Proceed to defrag ( using Windows Defrag or even Contig from
Sysinternals )

Any opinion on this are appreciated.

To protect your personal information and data from any future users
of average skills, you should, at the very least, format the hard drive.
You can do this using the original Installation CD. Simply boot from
the WinXP installation CD. You'll be offered the opportunity to delete,
create, and format partitions as part of the installation process. (You
may need to re-arrange the order of boot devices in the PC's BIOS to
boot from the CD.)

If you wish to do a more thorough job of protecting your personal
data, WipeDrive
(http://www.whitecanyon.com/wipedrive-erase-hard-drive.php) meets U.S.
DoD standards for securely cleaning surplus unclassified hard drives,
and could be used before formatting and reinstalling the OS and
applications. There are also several freeware utilities available for
this purpose, although they don't meet the DoD standards. Google is
your friend.


--

Bruce Chambers

Help us help you:


http://support.microsoft.com/default.aspx/kb/555375

They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. ~Benjamin Franklin

Many people would rather die than think; in fact, most do. ~Bertrand Russell

The philosopher has never killed any priests, whereas the priest has
killed a great many philosophers.
~ Denis Diderot

 

[Jim]

The first step removes the files from the folder. It does not delete from
the drive.
The second step does the same.
You left out emptying the recycle bin. This step makes it impossible to
restore the files, but it may still do nothing to the areas on the drive
which contain your "sensitive information".
The third step may overwrite the areas contained by your information. It is
not quite clear to me as to how the defrag program works.
All these steps do is a convoluted single pass overwrite. If you have
information that you really want to be as hard as possible to recover, then
a seven times overwrite is what you need.
Jim
I'd like to thank you for your information. Indeed I meant sensitive
information.

Since friday I've been thinking on this and I thought doing the
following:
- Delete the files I need to remove from disk
- Delete all temporary files including on local folders
- Proceed to defrag ( using Windows Defrag or even Contig from
Sysinternals )

Any opinion on this are appreciated.

TIA

 

[Dennis Dow]

All these steps do is a convoluted single pass overwrite. If you have
information that you really want to be as hard as possible to recover, then
a seven times overwrite is what you need.
Jim

I often hear people say that a 7 times overwrite is required. I always
answer “Show me.” Do date no one has given me any recent research
suggesting it’s required. Even Peter Guttmann who did the recovery on
MFM and RLL drives doesn't claim it's possible any more. A single pass
overwrite of data will remove the data. 7 times is an urban legend.

Now with that said, the empty of recycle bin, and defrag will NOT remove
sensitive data. It's important to get a wipe program that can wipe
freespace.

Dennis

 

[John70]

Thanks for your help. I will try to use a programa that I've found
through Google.

 

[Bruce Chambers]

7 times is an urban legend.

Not an "urban legend," at all, but rather a widely accepted industry
standard. In fact, it's even mandatory, by law, when wiping hard drives
belonging to some government agencies. (This is not to say that it's a
valid number, just that it's not derived from a baseless rumor, as you
imply.)


--

Bruce Chambers

Help us help you:


http://support.microsoft.com/default.aspx/kb/555375

They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. ~Benjamin Franklin

Many people would rather die than think; in fact, most do. ~Bertrand Russell

The philosopher has never killed any priests, whereas the priest has
killed a great many philosophers.
~ Denis Diderot

 

[Dennis Dow]

Not an "urban legend," at all, but rather a widely accepted industry
standard. In fact, it's even mandatory, by law, when wiping hard drives
belonging to some government agencies. (This is not to say that it's a
valid number, just that it's not derived from a baseless rumor, as you
imply.)

Well, as I already indicated, I suggest you read Peter Guttmann's work
on the topic. The 7 times came from his original research and even he
disputes the validity with modern drives.