The world of data recovery is a big mystery for most consumers and even some IT professionals. This is largely because hard drives themselves are complex devices and their technological specifics are not generally well known. Data recovery companies thrive on their customers lack of information and often get away with charging obscene rates for any recovery, regardless of complexity. I hope this article will be a helpful resource for consumers and professionals alike. I provide some basic information about data recovery by shedding some light on how hard drives work, how they can fail, what are the chances of successful recovery and how much the user can expect to pay. This information will enable the user to make an informed decision when choosing a data recovery company.

A bit about Hard Drives

A computer hard drive stores data on metal oxide platters which spin up to 10000 revolutions per minute. An actuator arm contains the head which reads and writes the data in the form of magnetic charges one millionth of an inch above the surface. Any given drive can have multiple read and write heads and each head can crash independently. A head crash occurs when the read/write head comes in contact with the platters of the disk (more on head crashes below). As manufacturers strive to cram more space on hard drives without increasing their physical size, the data gets written increasingly closer together, making for very difficult recovery should one or more heads crash. The brain of the hard drive is its controller board and this is unique for each individual hard drive. One other detail worth a mention is the service track of a hard drive. This is an area located on the outer part of the disk platter and it contains the drives firmware zone. The firmware of a hard drive is the information used by the computer to communicate correctly with the drive. These are the main components that make a hard drive work, now lets talk about what can go wrong.

There are many ways in which a hard disk can fail

Hard drives are extremely fragile and can suffer failures in many different ways, leading to a loss of data. The five most common types of drive failures are: logical errors, mechanical failure, electronic failure, firmware corruption, and bad sectors, or any combination these. Least severe of these is usually data loss due to logical errors.

Logical errors are often the simplest and sometimes the most difficult problems to deal with when recovering data. They can range from an invalid entry in a file allocation table, a simple problem that needs little work; to severe issues such as the corruption or loss of the entire file system. Logical errors can be spotted when files become inaccessible, there is a delay in starting up the computer, and programs do not run properly. Logical errors are often seen as simple because there is nothing wrong with the physical drive leading users to try recovering it themselves by using third party software. This is quite risky, however, as running such software on a damaged drive can result in total loss of data. The most effective way to prevent logical errors on your hard drive is to regularly use the Disk Defragmentation tool in your operating system. For more comprehensive information on preventing data loss, visit the tips section of our website.

Recovering a drive with logical errors can be simple and quick, however if the problem requires manual bit-by-bit reconstruction of the data, it can also be quite complex and time consuming. Normally, logical errors are in the lower end of the price range as they do not require manual disassembly of the drive, however there are cases when logical failures end up in the higher end of the price range. The bottom line with logical errors is the sooner they are caught and the less a user tampers with the drive, the better the chances for a quick and thorough recovery.

Mechanical failures are often much more serious than any other failure and frequently lead to a partial or even total loss of data. The most common type of mechanical failure is a head crash, which is when the read/write head comes in contact with the disk platter. Head crashes can be caused by a variety of reasons, including physical shock, static electricity, power surges, and mechanical read/write failure. Mechanical failures are detected by a constant clicking or grinding noise coming from the drive. If you suspect mechanical failure, you must immediately shut down your computer and call a data recovery company for advice.

Mechanical failures are usually the most severe and most challenging to recover from. All mechanical failures require physical disassembly of the drive. The replacement of a read/write head is one of the most complex and costly procedures that can be performed by a data recovery engineer, especially with larger capacity drives. The chances of recovery depend entirely on how much damage the drive has sustained, however they can be quite good. A crashed head does not mean that all your data is lost! Once again, the sooner you catch a mechanical problem and turn off your drive, the more of your precious data is likely to be rescued.

Electronic failures are most common after a power surge or due to some other electric problem, and the most common type is control board failure. A power surge can knock out the control board, making the drive undetectable in the BIOS. Because each drive is fitted with a unique control board, recovery of this type is relatively complex. However, the good news is that normally once the control board issue is fixed, the data is usually 100% recoverable.

Recovering a drive that has suffered from an electronic failure can be time consuming, mainly because the specific problem takes some time to diagnose. Once diagnosed, though, the recovery is usually not tremendously complex and would probably land in the mid-range in terms of price. Most of the time, we are able to achieve a 100% recovery from drives that have suffered an electronic failure.

Firmware corruption is caused by logical problems or physical damage to the firmware zone on the disk platter. When the firmware becomes corrupt, the computer is often unable to properly communicate with the hard drive, and drive is not recognized in the BIOS. Fortunately, when the drive fails due to firmware corruption, the data is usually fully recoverable once the drive has been repaired.

Recovering a drive that has suffered from Firmware corruption is possible with the use of our proprietary technology. Because the firmware information is isolated on the outer rim of the disk, most of the data can be recovered successfully. The complexity of recovering a drive that has suffered from firmware corruption depends on the amount of damage suffered by the service track on the disks platter. Expect the cost of this type of recovery to be in the mid- to high-price range.

Bad sectors are a common fate of all hard drives.

Eventually, all drives develop areas that are no longer functional and when this happens, they are isolated by the operating system. Bad sectors are very much like bumps in the road, areas which are avoided by the read/write head and which are no longer accessible to the user. If mission critical data exists on the drive, we recommend to backup as soon as possible, as the formation of bad sectors often indicates the impending demise of the drive. Finally, and most importantly, do NOT under any circumstances run the ScanDisk or Chckdisk utilities when data becomes inaccessible. These utilities are designed to fix only file system errors and not any other types of errors, so if your hard drive has suffered from bad sectors, these utilities only make things worse.

Bad sectors are accessible

We are able to recover drives with bad sectors using our proprietary mirroring technology. The process often involves manual mirroring bit-by-bit, which can be time consuming. The price of this type of recovery will generally be in the mid-range of the pricing schedule.

I hope the above explanations are of some use to all computer users. The basic fact is that data loss happens to everyone. Every hard drive crashes, and often when you least expect it to. Backup is essential for end-users and business users alike, and there are many excellent ways to back up your data. But if youve lost data, attempt to understand the problem before calling a data recovery company. Be informed, save your money, get your data back.

If I asked you the question: which part of your computer is the most fragile, what would you say? What if I asked: which part is most important to you?
Often, the answer to both of these questions is your Hard Drive.

Your hard drive is likely one the most important things you own. It contains work data, school data, emails, photos, music, movies, tax information, etc… Incidentally, the hard drive is also one of only two moving components in your computer (the other being your optical drive). The following is a list of important maintenance and monitoring techniques you can use to maximize the life of your hard drive and prevent data loss.

Hard drives are physically fragile – handle with care
Statistics show that 25% of lost data is due to a failure of a portable drive. (Source: 2001 Cost of Downtime Survey Results)
Contrary to its seemingly rugged appearance, your hard disk is a very delicate device that writes and reads data using microscopic magnetic particles. Any vibration, shock, and other careless operation may damage your drive and cause or contribute to the possibility of a failure. This is especially relevant for notebook users, as they are most at risk of drive failure due to physical damage, theft, and other causes beyond their control. That’s why we recommend regular backup of notebook hard drives, as often as possible.
Possible solutions include external USB or Firewire drives (although these are prone to the same risks), desktop synchronization, or backup at a data center through the web.

Hard drives write data in a non-linear way forcing it to become fragmented.
When files accumulate on your hard drive, they do not just get written in a linear fashion. A hard drive writes files in small pieces and scatters them over the surface. The fuller your hard drive becomes and the more files you save and delete the worse file fragmentation can be. Hard drive access times increase with fragmentation since your drive must work harder to find all the pieces of the files. The more fragmented your data is, the harder the actuator arm has to work to find each piece of a file.

A case in point: Disk fragmentation is a common problem for users of Outlook Express and database software. Each time outlook saves new mail, it does so in a different physical location from the previous time. This results in extreme fragmentation, causing longer hard drive access times and forcing more strain on the heads. This strain can eventually lead to a head crash, and often that means a virtually unrecoverable drive.Finally, in the event of a total crash, a fragmented drive is much more difficult to recover then a healthy defragged drive.

Luckily, Windows makes it remarkably easy to defrag your hard drive, simply launch the Disk Defragmenter utility (Start > Programs > Accessories > System Tools), choose which disk or partition you’d like to defragment and set it to work overnight or while you are not actively using your computer. Defragmentation will speed up your computer and ensure a longer life for your hard drive.

A very small power surge can fry a hard drive – use a UPS and turn off your computer when you can

Another little-known fact about the fragility of your hard drive is its susceptibility to electrical failure. An electrical failure can be caused by a power surge, lightening strikes, power brown-outs, incorrect wiring, a faulty or old power supply, and many other factors. If a power surge enters your computer, it may do an unpredictable amount of damage, including destroying your hard drive’s electronics or crashing the heads and possibly resulting in total data loss.
The best way to protect your computer from such dangers is to use a highly rated protected power bar or an Uninterruptible Power Supply (UPS). Although these devices won’t eliminate the chances of a crash, they will serve as effective protection in most cases. Also, you can minimize the danger of an electrical problem and reduce wear of your hard drive by turning off your computer or using power-save modes whenever possible. It’s a known fact that 100% of drives fail, the question is when will it happen and will you be prepared? Make sure to check out the knowledgebase section of our website for more detailed information on how electrical power affects your computer.

Be SMART, monitor the health of your drive to prevent unexpected crashes

All modern hard drives have a self-monitoring technology called SMART (Self Monitoring Analysis & Reporting Technology). What most people don’t realize is that the majority of hard drive failures do not have to be unexpected. Most failures occur as a result of long-term problems which can be predicted. By regularly monitoring disk health and performance, you can know about potential hard drive problems before you lose any of your data.

Several excellent utilities are available, including DiskView and Stellar SMART for standard IDE and SATA desktop drives. Also available are tools that monitor the health of SCSI drives and full RAID Array systems. Ariolic Software offers a great utility called ActiveSMART.

The only fool-proof way to prevent data loss is… Backup!
If you only take one of the suggestions here to heart, let it be this one: always back up your important data. After all the monitoring and all the prevention measures are in place, one fact still remains: all hard drives fail. Backing up regularly will ensure that you’re never caught without your critical data. For individuals, the simplest solutions include external portable hard drives, dvd’s, and online storage. For businesses, we recommend renting space at a secure data centre and implementing a disaster recovery plan, regardless of the size of your business.
I hope that the above techniques give you some idea of the importance of hard drive maintenance and provide some insights in how you can protect yourself from data loss.

Modern hard disks have greater storage capacities than their predecessors. Retaining the same physical size, they feature a much higher storage density, allowing storing more files on the same space of their surface. And hence the big problem: if your hard drive fails, you have a lot to lose. Much more than you would just a few years ago, with much less chances to get your data back without precision tools and clean labs.

While theres little you can do about a physically damaged hard drive except send it to a dedicated data recovery service, theres still hope if hard drive failure didnt cause it to stop spinning. Even if your disk is not accessible from Windows you can still access it with dedicated data recovery tools such as The Undelete NTFS Partition Recovery http://the-undelete.com/ntfs_partition_recovery.php or other FAT and NTFS partition recovery tools such as http://www.softinstitute.com/partition-recovery.html

These tools used by non-professionals can often recover damaged partitions and restore the hard drive to its original condition. Is it safe to use the same drive after it failed once? Maybe, depending on the reason of the failure. If data corruption occurred because of a system crash or a power failure, your hard drive is probably unaffected and should be used without a trouble. If a badly written application caused system instability and data corruption, its not your drives fault, and you should not be concerned about its reliability.

If, however, the instability was caused by the hard drive failure, exercise extreme caution. Have a look at the drives SMART logs accessible from Windows Administrative Tools, save your data onto another disk and replace the faulty one. And remember, even if your hard drive is completely inaccessible, you still have a strong chance of getting your data back with data recovery tools from http://the-undelete.com/