Guard Against Further Data Loss
By now, you probably have realized that you can not access your required data after some trouble shooting and worst of all, you do not have any backup. You are not giving up yet because you can not afford to lose your personal or business data. Seeking professional assistance seems to be the only way out but before you proceed, you need to ensure that the data media does not deteriorate further due to your action or decision just because you hit the wrong panic button. What are the things to look up for ? Here is the list.
Hardware related failure of disk drives
Besides impact, water or fire damage, power surge and improper handling, hard disk may fail on its own due to end of life. You may hear some unusual noise emitting from the hard disk when you attempt to power it up, or system may boot halfway and hang. In the boot up control BIOS, you are not able to see the disk details. In any case, if you observe one of these and suspect this is hardware related problem, notably the jittery disk crash, do not power on further. Immediately shut down the system. Believe it or not, this will help to preserve your hard disk's data from further damage.
One common mistake is to slave the drive in a usb casing to try reading the data using some commercial software relentlessly. Such practice should never be followed.
Logical failure
In the case when data is lost through deletion, virus attack, corrupted file system or any other unknown reasons, we classify this as logical related problem. Follow this rule regardless if you intend to do your own DIY recovery. Never install the utility and write the recovered data back to the same problem drive, as this will result in overwriting of data, Once data is overwritten, recovery is not possible.
Common Pitfalls Leading to More Data Loss
★ In Windows operating system, if the system prompt you to perform chkdsk, you should not proceed until you have backed up all your critical data. If the file system corruption is severe and your disk has developed bad sectors, it will result in even more data damage or eventually a "bricked" drive.
★ Modern laptops are commonly bundled with "recovery CD" or "recovery utility" on disk. If you take it literally, then you are in for big trouble. This is not to be used to recover your data, but rather a tool for you to re-install the operating system anew. Running this tool will result in complete or partial overwriting of original data.
★ If you can still access part of the data, make a backup copy somewhere before attempting to recover the rest. A bird in the hand is better than two in the bush. Otherwise here may be no bird later.
Encrypted File system - Some words of caution
If you have a disk encrypted with security software such as Bitlocker, Pointsec, Safeguard, Safeboot and the like, if you encounter problem and would like to do full disk decryption, it is risky to do it directly on the problem disk. Instead, you should err on the side of caution by making a clone of the problem disk and decrypt from there. Should the decryption goes wrong, you can still repeat another attempts. On the other hand, if you are not able to clone out the disk image successfully, this is telltale sign that the disk is having some hardware issues and it is unlikely that you can decrypt the drive directly without fixing the problem first. Please bear in mind that a failed decryption attempt is extremely hard to fix, if it can ever be done.
Sending your disk to unqualified vendors
There are simply too many heartbreaking outcries associated with this number one data killer when the media is sent to wrong hands. Prior servicing also tends to reduce the success of subsequent recovery attempt due to delicate nature of hard disks. Refrain from making slipshod and hasty decision to send the problem disk around, especially on the ground of cheaper price or just trying out. You may also want to learn more on how to select a data recovery specialist and do it right from the start.
The reality is this : if the disk drive has suffered hardware damages, it can only be rescued by hardware fix. Any utillity or software will only work when the disk is perfectly healthy and only suffers a logical corruption.