Free and Freeware Data Recovery Resources

Careful Painstaking Work Can Recover a Damaged .gz File

noreply@blogger.com (Paul D Pruitt) — Thu, 26 Jan 2012 23:18:00 +0000

http://www.gzip.org/recover.txt - "Here is how you can try to recover your data if it is extremely valuable to you. Do this only if it's worth it, because it will certainly take a lot of time, and it is not even guaranteed to get back all the data correctly. First, make copies of all the files you still have, to avoid deleting them by mistake. Then work only on the copies. You will also have to patch the gzip sources.

You must hope that all the bad sectors are somewhat grouped together. You can recover the portion before the bad sectors, and you may be able to recover some data after all bad sectors. You can't recover data bewteen those bad sectors, unless they are very far apart from each other.

To recover the portion before the bad sectors, just do:

gunzip < damaged.gz > part1

gunzip will stop when it sees the bad data. All data in the file "part1" is guaranteed to be correct, but of course the rest will be missing. If the file "damaged" is a .tar file, you can recover some files with:

gunzip < damaged.tar.gz | tar xvf -

gunzip and tar will complain at some point, but tar may have recovered some files already.

Now let's try to recover something after the bad sectors. You first have to find the boundary of the first undamaged compression block after the damaged portion. The boundary is bit aligned. To find the damaged portion, add

fprintf(stderr, "bytes_in %ld\n", bytes_in);
before:
error("invalid compressed data--format violated");

in unzip.c. Then round bytes_in this to the next disk block boundary and create a new .gz file by concatenating a valid .gz header and the data believed to be undamaged. Then try repeatedly "gzip -t" on the new .gz file, removing from 1 bit to 8*64K bits from the compressed data portion, until you get a crc error instead of a "format violated" error. At this point do

gunzip < damaged.gz > damaged

The gzip CRC will always fail because you will miss some 'history', but after some time, the history effect will be reduced and you might be able to recover part of the data. You will have no guarantee that the data will be correct except by manual inspection.

To get a valid .gz header, look at the file algorithm.doc in the gzip distribution, or just copy the header from any valid .gz file. The header ends at the zero terminated file name. To speed up the search for a block header, the first 3 bits should be 0,0,1 (starting from least significant bit) so that when aligned on a byte boundary you get first_byte & 7 == 4. So you only have to test about 1/8 of all possible bit alignments. Of course if your block was not byte aligned
you have to bit-shift the entire file.

As you can see, all this is not a trivial task, so you should attempt it only if your data is very valuable. gzip 2.0 will have a new blocksize option, allowing to recover easily all undamaged blocks after the damaged portion.

Jean-loup Gailly

jloup@gzip.org
http://www.gzip.org"

Fixgz Fixes Binary Files FTPed as Text Files by CR When it Is Followed by LF

noreply@blogger.com (Paul D Pruitt) — Thu, 26 Jan 2012 23:04:00 +0000

http://www.gzip.org/fixgz.zip - "99.9% of the problems with gzip are due to file transfers done in ASCII mode instead of BINARY mode. In particular, gopher is known to corrupt binary files by considering them as ASCII. Make sure that your local copy of the file has exactly the same byte size as the original. If you have transferred a file in ASCII mode and you no longer have access to the original, you can try the program fixgz to remove the extra CR (carriage return) bytes inserted by the transfer. A Windows 9x/NT/2000/ME/XP binary is here. But there is absolutely no guarantee that this will actually fix your file. Conclusion: never transfer binary files in ASCII mode." - Presumably this works with any file binary transferred as ASCII rather binary. Maybe it works with files mistakenly opened it Word or Notepad...I don't know.

Only Tody Install GRT Recover My Files for Free as in Freeware

noreply@blogger.com (Paul D Pruitt) — Tue, 27 Dec 2011 14:55:00 +0000

http://www.giveawayoftheday.com/grt-recovery-my-file/- "GRT Recover My File is fast and easy-to-use data recovery solution. No technical or data recovery skills are required to undelete your files.

GRT Recover My File tool helps you to recover lost files from FAT16, FAT32 and NTFS"

Firefox Add-Ons Disappearing

noreply@blogger.com (Paul D Pruitt) — Tue, 20 Dec 2011 04:12:00 +0000

Apparently when users updated to Firefox 7.0 many if not all users experienced their add-ons disappearing fro the add-on manager. The first fix come from this additional add on: https://addons.mozilla.org/en-US/firefox/addon/fx7-recovery/. however the problem has now been fixed in Firefox 7.01 and since Firefox appears to now be at 8.01 and available here: http://www.mozilla.org/en-US/firefox/new/, there appears to be doubly no reason to download this add-on...

Only Today: AyRecovery Lite Available for Free - Replaces System Restore

noreply@blogger.com (Paul D Pruitt) — Fri, 02 Dec 2011 14:25:00 +0000

http://www.giveawayoftheday.com/ayrecovery-lite-2/ - "AyRecovery Lite is a HDD instant recovery program and also a must-have toolkit for every PC owner. It is the easiest solution to restore and recover your system and precious data to working status at startup in seconds.

AyRecover Lite can effectively prevent your PC from system crash, virus attack, failed software installation, user error and other problems. If your Windows doesn’t load, just reboot your PC and everything will go back to the way it was.

AyRecovery Lite can easily remove PC failures like system problems, IE corruption and so on. It will protect the whole hard disk for you."

Help Recovering An Excel (Also Maybe Word, PowerPoint and Open Office) File After a Blackout

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 15:02:00 +0000

If you have Excel 2010 or maybe Mac Excel 2011, see this article:
http://www.makeuseof.com/tag/recover-unsaved-ms-word-2010-document-seconds/#disqus_thread. This article applies to Word and PowerPoint as well.

Also try right clicking on the file in Explorer or My Computer, choosing Properties, then choosing the Previous Versions tab and try to recover a previous version.

Otherwise or also see my article on Excel recovery here: http://s2services.com/excel.htm. For Word an equivalent article is here: http://s2services.com/word_repair.htm. For Open Office an equivalent article is here: http://s2services.com/open_office.htm.

In regards to commercial software, recovering previous versions can be done by RecoverMyFiles - http://www.recovermyfiles.com/ and the Abstradome series: Word Regenerator http://bit.ly/si9aOt, Excel Regenerator - http://bit.ly/jVMIZC or PowerPoint Regenerator - http://bit.ly/ut6Ofb.

Recovery Toolbox for Live Mail E-mail Recovery

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:40:00 +0000

Mail Undelete Recovery Toolbox Free - "If you have been using email software for quite a while, you know what kind of problems an inadvertently or erroneously deleted email or contact can result in, especially if you urgently need it a few weeks after. Although Windows Mail/Live Mail won't be able to help in this situation, you can always use a third-party tool, such as Mail Undelete Recovery Toolbox Free."

Digital Video Repair List

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:37:00 +0000

http://www.videohelp.com/tools/sections/video-repair-fix - lists 16 pieces of software, with most of them freeware, for repairing corrupt digital video.

New Zip Fixer Freeware - Zip2Fix: extract undamaged files from a corrupt ZIP archive

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:33:00 +0000

http://leelusoft.blogspot.com/2011/06/zip2fix-10.html

CD Recovery Toolbox

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:32:00 +0000

http://www.oemailrecovery.com/cd_recovery.html - "Recover files from damaged or corruptedCD/DVD/HD DVD/Blu-Ray disks...CD Recovery Toolbox (download, mirror) tool was developed for recovering damaged files from different disk types: CD, DVD,HD DVD, Blu-Ray, etc. You can use it to restore information lost as a result of some mechanical damage of the disk (scratches, chips, different spots on thesurface) or as a result of incorrect recording. Thus, the program can recoverdata that was considered lost. The CD Recovery Toolbox Free tool scans any CD and DVD disks and finds files and folders located there. We should mention that there can be some information on the disk that cannot be recovered. Not all of the files and folders can be found - that depends on the degree and location of the damage."

Recovering Corrupt doc, xls & ppt Files Created with Office 2007/2010

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:30:00 +0000

I had the luck of getting a corrupt xls file a few days ago that revealed to me a new method for recovering corrupt Excel files. Apparently the file was a hybrid of xls and xlsx code. To recover the data I used my effective zip repair program (Zip Repair Pro, although free ones might work too), which recognized the zip parts and removed the rest. The file ten immediately opened as an xlsx file. Well maybe that isn't entirely true, but Excel was able to display a bona-fide spreadsheet after doing a little of its recovery work on the file.

So this reveals to me a new kind of corruption, hybridization between the old format Office 97-2003 (BIFF) files and the new zipped Office 2007/2010 (Office Open) format files.

Free Version of the Mac Software Disk Drill

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:29:00 +0000

http://www.cleverfiles.com/pro.html - the free version of Mac software Disk Drill provides Data protection, scans for S.M.A.R.T. disk issues and allows the making of backup copies of partitions for instance to save data from a failing disk. The program also apparently will scan
for lost files but you have to pay for another version to actually recover the files.

DiskInternals Linux Recovery

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:25:00 +0000

http://www.diskinternals.com/linux-recovery/ - DiskInternals Linux Recovery is a handy no-cost utility that runs under any version of Windows and designed to recover the erased or damaged information that is kept on Ext2/Ext3 partitions.

DiskInternals Linux Recovery might come in handy on a number of occasions when due to the unforeseen contingencies there was a loss of important data stored on Ext2/Ext3 disks.

DiskInternals Linux Recovery can recover both the files you just accidentally deleted and the files which have been erased long time ago. It's also capable of restoring corrupted files and can read and recover the information located on an inaccessible drive. The files you restore can be saved on any (including network) disk, which is visible to the host operating system.

The utility also allows you to repair a corrupt or damaged partition table and attempt to restore a disk after a serious crash, so you'll have a chance to repair a serious malfunction right away.

Video-Repairer

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:24:00 +0000

http://www.redsofts.com/soft/119/28642/VideoRepairer.html - "Video-Repairer is a handy tool that help you one click to Repair Video files which can not be played or dragged. Video-Repairer can Repair files which are not completely downloaded from http ftp rtsp mms and so on. After being Repaired, these files can be played fluently and dragged at your will. Video-Repairer also can Repair the Video files that can't be dragged while they are playing. After being Repaired, these files can be dragged at your will. Video-Repairer has another function
that it can try to Repair partly damaged and corrupted Video files. The Repaired files can skip the damaged data block, and continue to play. When palyers such as Mediaplayer and realplayer hint that the multimedia file can't be played or it has been damaged,you can try to
use the Video-Repairer to Repair the file. The Repaired files by Video-Repairer can be opened by multimedia edit software such as VirtualDub to be further processed. The rate of success in the Repair has reached 80% to 90%. Note:Our company shall not be responsible for the damaged file in the course of Repair." - May be Russian.

STL File Repair

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:08:00 +0000

STL files are 3 dimensional CAD type files where the 3 dimensional objects are built up using usually a huge number of triangles. These files are used by the "rapid prototyping" industry to make prototypes of objects or parts using milling machines, "3D Printers" and other
similar technologies that build up 3 dimensional objects either by starting with a large block of material and whittling it down to the desired object, or by building one up a layer at a time. The physical material is typically wood (in a milling instance) or plastic, some kind of resin or even metal, which can now be annealed one thin layer at a time by prototype machines.

My understanding is that these STL files when converted from other 3 type files, sometimes or often need repair before they a usable by a prototype machine. The freeware below will repair such files as I gather any good stl editor should.

http://www.varlog.com/products/admesh/ - Admesh features:
* Read and write binary and ASCII STL files
* Check STL files for flaws (i.e. unconnected facets, bad normals)
* Repair facets by connecting nearby facets that are within a
given tolerance
* Fill holes in the mesh by adding facets.
* Repair normal directions (i.e. facets should be CCW)
* Repair normal values (i.e. should be perpendicular to facet with
length=1)
* Remove degenerate facets (i.e. facets with 2 or more vertices
equal)
* Translate in x, y, and z directions
* Rotate about the x, y, and z axes
* Mirror about the xy, yz, and xz planes
* Scale the part by a factor
* Merge 2 STL files into one
* Write an OFF file
* Write a VRML file
* Write a DXF file
* Calculate the volume of a part

Windows 9x Password Hacker

noreply@blogger.com (Paul D Pruitt) — Sun, 20 Nov 2011 14:06:00 +0000

http://www.mitec.cz/Downloads/PwdHack95.zip - Windows 9x Password Hacker

Re: Nice - Free MDB Repair: Recovery Toolbox for Access

noreply@blogger.com (Paul D Pruitt) — Fri, 15 Jul 2011 21:54:00 +0000

Sorry, this may be a demo version...

On Jul 15, 5:43 pm, socrtwo <socr...@gmail.com> wrote:
> http://www.mdbrepairfile.com/- "Recovery Toolbox for Access is a
> powerful Microsoft Access database repair tool spe-cifically designed
> for recovering data from damaged Microsoft Access database files and
> making easy recovery for Access possible. The program supports
> standard database files with *.mdb and *.accdb extensions."

Nice - Free MDB Repair: Recovery Toolbox for Access

noreply@blogger.com (Paul D Pruitt) — Fri, 15 Jul 2011 21:43:00 +0000

http://www.mdbrepairfile.com/- "Recovery Toolbox for Access is a
powerful Microsoft Access database repair tool spe-cifically designed
for recovering data from damaged Microsoft Access database files and
making easy recovery for Access possible. The program supports
standard database files with *.mdb and *.accdb extensions."

Recover Unsaved Drafts of Documents with MS Office 2010

noreply@blogger.com (Paul D Pruitt) — Sat, 18 Jun 2011 02:19:00 +0000

http://www.makeuseof.com/tag/recover-unsaved-ms-word-2010-document-seconds/#disqus_thread
- unsaved drafts are now kept for 4 days. That means if you never
bother to save a a document, spreadsheet or presentation, you can
still retrieve it with MS Office 2010.

Winzip Methods to try fixing invalid Zip files with the command line add-on

noreply@blogger.com (Paul D Pruitt) — Fri, 03 Jun 2011 19:54:00 +0000

http://kb.winzip.com/kb/entry/126/ - "The WinZip Command Line Support
Add-On contains functions that attempt to repair Zip files (.zip
or .zipx). The appropriate versions are listed on and can be
downloaded from the Alternative Download Links web page. If you are
using a version earlier than WinZip 11.2, you can download the
appropriate add-on version from the Legacy Download Links page. Access
to a Command Prompt window will also be necessary..."

How To Recover Lost Files In Dropbox

noreply@blogger.com (Paul D Pruitt) — Fri, 27 May 2011 02:50:00 +0000

http://www.makeuseof.com/tag/recover-lost-files-dropbox/ - "But what
happens if you accidentally delete a file? Will it be gone forever
once the changes are synced to Dropbox? Yes, the file will disappear
from your Dropbox folder. However, it won't be entirely gone just yet.
So is there a way to recover lost files from Dropbox after it was
deleted? This being the super smart Dropbox, there certainly is!..."

Free Python Script for Repairing .mov Movie Files - http://s2services.com/hosted-freeware/repair_cycorder_mov.zip

noreply@blogger.com (Paul D Pruitt) — Thu, 12 May 2011 16:40:00 +0000

http://s2services.com/hosted-freeware/repair_cycorder_mov.zip

Repairs Damaged .mp4 Files that Show No Video

noreply@blogger.com (Paul D Pruitt) — Thu, 12 May 2011 16:35:00 +0000

http://www.macupdate.com/app/mac/19769/isquint - includes a program
droplet called "Debreaker" to repair damaged "no video" .mp4 files

For Those of Us Who Can No Longer Open Excel Files Outside of Excel 2007 - http://goo.gl/GgW2R

noreply@blogger.com (Paul D Pruitt) — Sat, 23 Apr 2011 02:25:00 +0000

http://sympmarc.com/2010/02/04/microsoft-excel-error-there-was-a-problem-sending-the-command-to-the-program/
- ". There's a setting in Excel 2007 which prevents it from opening
files if the request comes via Dynamic Data Exchange (DDE), and it is
enabled by default. Go to the Office Button / Excel Options /
Advanced, and scroll all the way down to the General section. There
you will see the "Ignore other applications that use Dynamic Data
Exchange (DDE)" setting checked. Uncheck the box, click OK to apply,
and you're good to go..."

For Those of Us Who Can No Longer Open Excel Files Outside of Excel 2007 - http://goo.gl/GgW2R

noreply@blogger.com (Paul D Pruitt) — Sat, 23 Apr 2011 02:20:00 +0000