Blank CDs and DVDs have been around for quite some time now and their
limited life span means that many users will eventually run into
accessibility problems. With age come problems to read files from the
CDs or DVDs. The only option in this case is to make use of data
recovery software to save those files to storage device before they
become completely unrecoverable.
Why can files become unreadable
on optical media? Burned CDs and DVDs suffer from material degradation.
And most disks also suffer from oxidation, not to mention scratches and
other forms of physical contacts. The average lifespan of such disks is
said to be ten years.
This overview looks at free solutions to recover files from CDs and DVDs.
It
should be obvious that data that is not there anymore physically cannot
be read by even the best DVD or CD recovery software. Sometimes though
files can not be read by the user in Windows, while they are largely
recoverable on the byte level. Basically, data recovery software copies
every readable byte of the optical disks to another storage device.
What the developer says:
It supports all optical disc formats and all common optical disc file-systems. Start up IsoBuster, Insert a disc, select the drive (if not selected already) and let IsoBuster mount the media. IsoBuster immediately shows you all the tracks and sessions located on the media, combined with all file-systems that are present. This way you get easy access, just like explorer, to all the files and folders per file-system. Instead of being limited to one file-system that the OS picks for you, you have access to “the complete picture”. Access data from older sessions, access data that your OS (e.g. Windows) does not see or hides from you etc.
IsoBuster is available as a
free and professional edition. The free version has several
limitations, largely lack of HD DVD, Blu-Ray and file format support.
The
program tries to install a toolbar during installation, make sure to
cancel that before continuing. The program is simple to use. It will
automatically recognize a CD or DVD that has been inserted into the
drive. The sessions, tracks folders and files are displayed in the
program interface.
Here it is possible to navigate the menu
structure, and extract individual files or files from folders from the
disk. IsoBuster displays a Save As dialog and extracts the data to the
selected disk.
Several recovery options can be configured in the
preferences. This includes the maximum number of retries, sorting
criteria, file system specific settings or image files handlings.
IsoBuster can load CD and DVD images as well, which is the recommended
way of handling recoveries.
What the developer says:
CD Recovery Toolbox Free – repair damaged CD disks
CD Recovery Toolbox 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.
This program is very easy to
use. CD Recovery Toolbox supports recovery of CD, DVD,HD DVD and Blu-Ray
disks. It begins with the selection of the drive, and the output
directory. The program then reads the files from the disk and displays
them in a file browser.
Here it is possible to select the root
folder, or one of the subfolders of the disk for recovery. A click on
Save reads the data from the disk and saves it on the selected storage
device.
What the developer says:
As your CD and DVD collection grows, there are two important problems you face – do your CDs and DVDs still work? What can you do when a CD or DVD starts to have problems? These are crucial questions since the discs are used to store valuable files like email, home movies, photographs, business/tax records and music. The solution is to use a free program like CDCheck. It can scan most CDs in a few minutes to tell you if the data is OK – this way, you don’t have to find out the hard way that there is a problem. Plus you can use the time it takes for a scan to complete as indicator of the CD or DVDs overall health – even though files may not be recorded as damaged, slower results normally indicate a CD that is on the way out (expect longer times if there are more files on the CD).
If a CD or DVD is showing files with damage or you can no longer read a file in a drive, CDCheck can be switched to recovery mode and make a full sweep of the CD or DVD, recovering lost files along the way. When parts of a file can’t be fully recovered, the program will still recover any salvageable fragments. Many file formats such as Zip, TIFF and JPEG can still be used if incomplete (success of this technique varies, depending on the damage). Most zip tools have a ‘repair archive’ function, and a standard graphics editor can help repair damage to photographs caused by missing fragments.
CD
Check is a software that needs to be registered on the developer’s
homepage before it is free to use for a lifetime. The program can check a
disk for read errors, which the other programs in this overview cannot.
The time of each check depends on the disk and the speed of the drive.
The
other options are to compare directories, for instance a directory on
the CD or DVD with a local directory, and to recover files from the
disk. For comparison purposes, hashes are generated.
What the developer says:
CD, DVD and BD media keep their data only for a finite time (typically for many years). After that time, data loss develops slowly with read errors growing from the outer media region towards the inside.
Archival with data loss protection
dvdisaster stores data on CD/DVD/BD (supported media) in a way that it is fully recoverable even after some read errors have developed. This enables you to rescue the complete data to a new medium.
Data loss is prevented by using error correcting codes. Error correction data is either added to the medium or kept in separate error correction files. dvdisaster works at the image level so that the recovery does not depend on the file system of the medium. The maximum error correction capacity is user-selectable.
DVD Disaster is not a typical
data recovery software, as it can be used to prevent data recovery by
adding error correction codes to optical disks. To create error
correction codes a disk image is required. The program is able to create
those disk images and create the codes. Those codes can then later be
used to recover files from a disk.
Roadkil’s Unstoppable Copier
What the developer says:
Recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts of the file were not recoverable in the end.
The program can be used as a daily backup system using its batch mode functions. A list of transfers can be saved to a file and then run from the command line to perform the same batch of transfers on a regular basis without having to use the GUI interface. The program supports command line parameters which allow the application to be run from schedulers or scripts so it can be fully integrated into daily server tasks.
Roadkill’s
Unstoppable Copier can read data from any kind of disk. It tries to
recovery files on a byte level, and can copy files partially because of
this. This often means that files can still be accessed, especially if
they are not binary.
What the developer says:
Abyssal Recovery can rescue corrupted or lost data from damaged, scratched, or defective CD and DVD discs. Abyssal Recovery can copy the files to another destination on your hard drive. Abyssal Recovery will skip the bytes which are not readable from file and copy all other bytes to extract maximum data. You can set the program to copy byte with byte to minimize the losses, or you can set a higher number of bytes to be copied once for a faster recovery.
Abyssal Recovery
is a basic CD and DVD data recovery software that tries to rescue data
from partially unreadable disks by copying all readable bytes to another
storage device. It does not offer an advanced feature set as several of
the other recovery solutions in this guide.
Verdict
Two
of the tools in this review can be used to prevent data loss. Both CD
Check and DVD Disaster offer the means to check data on disks regularly
to ensure 100% readability of the data. DVD Disaster even offers a
solution if data becomes unreadable.
For disks with corrupt data,
IsoBuster is probably the prime choice. Even though it may make sense to
use several tools for best recovery results.
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