A Beginner’s Guide to Data recovery
Hard Drive data recovery
When you lose data on your hard drive, you basically have two scenarios: a) you can still access your hard drive, and everything is ok with your operating system or b) your computer froze and doesn’t boot up, and possibly weird noises come from the hard drive.
Let’s tackle scenario a) first, with simple, easy to follow rules.
1. After data loss, never write to the hard drive.
When data is lost on a hard drive, the first rule you should follow is a simple rule of common sense: don’t write anything to that hard drive, until you recover what you’ve lost.
There is a very simple reason for this: when you delete something from your hard drive, the operating system (windows, mac os and linux for example) does not permanently delete that information. Instead, it only tells you that there is more free space – that space is still occupied by your deleted information, but it changes it state, from occupied to free.
One thing is true when it comes to data on your hard drive – what you see is not all you have on your hard drive.
This is true for lost files, but also for lost partitions. If you delete a partition, just leave it blank. You can’t see it, but data recovery software can. Same thing with formatted hard drives – you can still recover from a full format.
How do I delete files forever? If you want to erase files for security and/or privacy reasons you should use commercial software that does that job or contact a specialized data recovery company.
2. Restore your backups
If you did your homework, you should have up-to-date backups of all your vital information. This is the time to check on those backups, and eventually restore them, in order to retrieve the lost data.
In the unlikely event that you don’t have up-to-date backups of your data, you must start the process of data recovery, as explain in the following steps. But remember that in the future backups are your best chance of protecting vital and irreplaceable information. So back up often and store your backups in a safe location.
3. Don’t install data recovery software on the same hard drive where the data loss occurred
Remember step 1. If you install any software to the same hard drive where you lost data, you could overwrite that lost data forever.
4. Turn of your computer
To play it safe, right after your data loss, you should turn off the computer. Even the routine operation of the operating system depends on reads and writes from and to the hard drive, and your lost data can be overwritten in one of those.
5. Protect the hard drive
Remove the hard drive from the computer and connect another one, even an old one, as long as it had an operating system installed, so you can boot up your computer and later on analyse the hard drive where data loss happened. As an alternative, you can install your hard drive in another working computer, as a secondary drive, so you can access it without writing to it directly.
If your data loss happened because of a virus attack, be sure to have anti-virus software installed on the new hard drive.
Rescue disks to the rescue: If you are afraid of taking your computer apart, and you have a pre-prepared “rescue disk”, you can boot your computer from a bootable floppy disk, CD or DVD and go from there.
6. Chose your data recovery software
There are several freeware choices on the Internet, as well as many demos of well known commercial software programs.
You can try, at your own risk experimenting with these programs. In any case, if you have any questions, doubts, or don’t have the technical expertise to recover the lost data by yourself, you can always consult a data recovery company in your area.
Scenario b) happens when hard drive failure occurs.
A hard disk failure occurs when it becomes impossible to access the hard drive, due to internal or external factors. The factors vary, but the most common one if known as “head crash” – the head that reads the magnetic surface of the disk touches the metal surface, grinding against it and making normal reads impossible.
What makes up a hard drive? Platters, a motor, reading/writing heads and head actuators. The platters rotate using the motor and the heads read and write information in the place they are moved to by the actuator arm.
1. Shut off the computer and don’t try to restart it
When a physical error occurs in a hard drive, the best thing to do is not to try to restart the computer system. Further damage can be done to the hard drive if you try a restart.
2. Secure the hard drive
If your hard drive failed because of an external problem, you should preserve the hard drive as-is. This means that, for instance if you had a flood and the hard drive came in contact with water, you should preserve the hard drive in water, and never try to open or dry it by yourself.
My computer was underwater! In this case, the best thing to do is to take your hard drive out and store it in a plastic container full of water. You will send that container to the data recovery company.
2. Choosing a data recovery company
When a physical error occurs you shouldn’t try to fix it by yourself. Many times components must be repaired or even replaced and that can only happen in a clean room environment.
To maximise your chances of recovery, you should quickly find a data recovery company near you.
There are 4 main things you should consider when choosing a data recovery company:
a) The right equipment. The company you choose should have the right means to analyse and recover your lost data. Ask directly if they have at least one class 100 clean room.
b) A partnership opportunity. Will that company forge a partnership with your company? Do they offer training and long-term advices on how to better protect your data?
c) Expertise. Does that company specialize in the media you are trying to recover?
d) List of clients. Check out their website and the list of past clients. Does that list include big names, and a wide array of different industries? That is always a plus.
3. Send the hard drive for analysis
Most data recovery companies don’t charge you anything if they can’t recover your data. They will probably give you an estimate on how much you are going to spend before you have to pay anything, so take advantage of that.
Shop around for better prices, but remember step 2 – sometimes it’s worth it to pay something extra, if you get better equipment and a better track record working for you.
When you decide, send your hard drive in for an estimate. Use preferably the wrapping material that came with your hard drive. If you bought the hard drive along with your computer, use a soft wrapping material, such as an anti-static electrostatic discharge (ESD) bag. Use foam to secure the hard drive inside and prevent sudden movements.
David Marques
Technical director
Data Recover Center
Recuperação de dados
