Inability to access your data stored on the data storage device could be caused by many reasons, from those that are easy to fix to those which are completely impossible to fix. If the damage is irreversible then data loss will occur. The causes of the failure of your hard drive or CD-ROM drive could vary from a bad connection due to a loose wire (which is easily recoverable) to damage to the media itself, which could still be recoverable in many cases.

As in the medical profession, the first principle of data recovery is: "do not harm".

If you are facing a data loss situation, what not to do is very important!

• Do not power up a device that has obvious physical damage.
  

• Do not power up a device that has shown symptoms of physical failure. For example, disks that make "obvious mechanical fault noises" such as ticking or grinding, should not be repeatedly powered on and tested as it just makes them worse.
  

• Activate the write-protect switch or tab on any problem removable media such as tape cartridges and floppies. (Many good backups are overwritten during a crisis.)
  

• Do not use free software. This is very important. Free data recovery software can be extremely dangerous and ruin your chances for a successful data recovery. Many companies offer free data recovery software -- also called Do-It-Yourself (DIY) data recovery software -- available for download on their website.
  

Even the best programs only work in very specific situations. While these free tools that are available may help, they usually only help if you are encountering one of a very few specific data loss situations.

Some programs may cause further or permanent data loss. While these programs

Anyway, there is something you CAN do; if you are having data access problems and your media has no symptoms of physical failure or damage, try and check some obvious issues before deciding if you need data recovery:

• Are the power and disk cables properly connected?
  

• Is configuration or disk information correct?
  

• Try the defective unit with a different adapter/controller interface or on a different computer.
  

• Is there an experienced technician at a local store or the company help desk that you can consult, if these steps are beyond your capabilities? (Make sure whoever is in contact with your data loss situation is fully aware that they should do nothing during their troubleshooting that will risk hurting your data.)
  

Doesn’t work? Don’t panic; if the damage occurred to the drive's electronics, it most likely could be fixed. If the damage occurred to the, for example, system areas of the disk, leaving the data zone intact, those data could be theoretically, and (in some cases) practically, recovered by a professional.

Look on the Net for data recovery companies, ask them questions, explain them your situation. In most cases they will be able to understand your problem and fix it for a fair price.

Emanuele Allenti is the owner of http://www.hard-disk-data-backup-recovery.com - a website containing tips and useful information written by experts for those interested in backup and data recovery