The following tips will improve your chances of a successful recovery and prevent you from accidentally taking actions that could cause additional damage or reduce the chances of a successful recovery.
What to Do When a Hard Drive Fails
Physical damage: Disconnect the power immediately if the disk produces unusual noises (eg, clicking, grinding), or you experience missing files, jumbled file names and excessively slow system operation. This will prevent the read/write heads, platters, spindle and other components of the hard drive from sustaining serious damage.
Logical damage: Unplug the computer directly from its power source (or wall) if you lose data due to file deletion, accidental formatting or another logical error. Following proper shutdown processes will likely overwrite some of the data, exacerbating the damage. (When a computer deletes a file, it does not actually overwrite the data until it needs the space, it only removes relevant entries in the file tables. Using the computer in any way will reduce your chances of recovering the data successfully.)
New software or hardware installation: If your data becomes inaccessible after you installed software or computer peripherals (eg, PCI card, sound card, or USB-powered accessories) systematically reverse the last few installations. If this does not help, power down the computer.
Electronic failures: Remove the drive and slave it into a working computer if it does not make any noise and will not show up in the computer’s BIOS (or equivalent). Send it for professional repair if it continues not to be detected.
Firmware damage: Immediately shut down your computer if it fails to load its operating system, presents incorrect drive information (eg, wrong size, wrong model number), unreadable files or incorrect file names. Firmware problems can cause wrong placement of the read/write heads and corrupt your data.
Removing the hard drive: If you decide to remove the hard drive from the computer shut down the computer and unplug it from the power source and ground yourself properly before touching any components to avoid static damage to the computer's circuit boards.
DIY recovery attempt: If your hard drive does not have physical damage the only attempt at DIY recovery we recommended is to slave it into a working system to check for readiness and file system integrity. If you ascertain that only the operating system is corrupt or the original host computer has a hardware issue you may be able to copy your data easily.
RAID: Switch off the server and immediately call professional help if you value the data on your array.
SQL server: Make a copy of the database and log files on an alternate physical drive prior to attempting any repairs, opening a support ticket with Microsoft or submitting the database to a data recovery service provider. Provide your data recovery service provider with the database structure and a list of priority tables.
MS Exchange: Make a copy of the .EDB, .STM and .LOG files before attempting any repairs, opening a support ticket with Microsoft or submitting the database to a data recovery service provider.
Data backup strategy: Back up your data early and regularly, with at least one off-site backup to protect against fires and environmental disasters.
Call professional help if you are not 100% sure you will be able to recover the data on your own, of how to do any of the above or of what to do next.
What Never to Do When a Hard Drive Fails
Never assume that lost data is irrecoverable.
Never operate a hard drive that makes unusual noises as this can cause serious damage to the drive.
Never install new software or hardware on a computer without an up-to-date data backup.
Never operate a hard drive after accidentally deleting files. (When a computer deletes a file, it does not actually overwrite the data until it needs the space, it only removes relevant entries in the file tables. Using the computer in any way will reduce your chances of recovering the data successfully.)
Never install data recovery software on the same drive/partition containing your lost data; you will likely overwrite the data with the installation.
Never open your hard drive; you will expose sensitive components to contamination and damage. In addition, hard drive components are extremely precise and cannot be serviced by common IT professionals or technicians.
Never swap circuit boards or replace the electronics on your hard drive. This can cause firmware/system conflicts that may result in major problems.
Never operate your drive if was damaged by a liquid. The moisture will cause head contact that will destroy the drive.
Never run the recovery software furnished with your PC. It serves only to restore the system, not your data and can overwrite your data.
Never take the advice on recovering data on a RAID array from OEM support staff unless they are 100% sure of the current configuration.
Never attempt to rebuild a RAID array unless you are sure which drive failed, why it failed, and when it failed.
Never restore a database before making copy of the current database files.
Never use third party SQL recovery and utility programs on the original database files.
Never attempt to defragment a data store containing mail server or database file. This often causes data store to be inconsistent, resulting in data corruption.
Never attempt to recover data if you are not sure why your hard drive failed or why data was lost.
Never place a fire-damaged drive in refrigerator to cool it. Let it cool naturally and send the entire computer for recovery.
Never attempt to dry a water-damaged drive by exposing it to heat. Instead, place the drive in a sealed anti-static/plastic bag that will keep it damp before shipping.