Data Recovery Doctor

What is data recovery?

Data recovery is the process of salvaging data from damaged, failed, wrecked or inaccessible primary storage media when it cannot be accessed normally. Often the data is being salvaged from storage media formats such as hard disk drive, storage tapes, CDs, DVDs, RAID, and other media. This can be due to physical damage to the storage device or logical damage to the file system that prevents it from being mounted by the host operating system. Although there is some confusion as to the term, data recovery can also be the process of recovering deleted information from a storage media.

Deleted and overwritten data

When a file is deleted, in fact the data is not gone. The operating system simply marks the file as deleted in File Allocation Table (FAT) and tells the Operating System the space allocated to the file is available for writing but the actual data in the hard drive is untouched. The space allocated to the file is then made available as free space, and as the computer is used, new data may be written to that same space. Before this is done, the data is still intact and can be recovered by a variety of different advanced data recovery tools specially designed by Data Recovery Doctor. These tools can see the files from an entirely different perspective as they use a customised Operating System. These tools in used in combination to some other data recovery methods, enable Data Recovery Doctor to retrieve the data from the corrupted partitions. If the free space used by the deleted file is occupied by another file or in other words the deleted file is OVERWRITTEN, the task of data recovery will become extremely difficult.

A common misconception is that overwritten data, as described above, can be recovered by different advanced data recovery tools. You have to remember that in fact data is recorded onto magnetic media such as hard drives by writing a pattern of pole changes that represent binary "ones" and "zeroes". These patterns are then read back by the disk and translated by the operating system as text, executables, pictures or whatever the data may represent.

If the data is overwritten with a pattern of bits (ones and zeroes), the magnetic fluxes will be physically changed and the disk will only detect the new patterns when it is reading the data. This makes the data effectively, and for all intents and purposes, erased.

However if the data loss has happened as result of logical or physical damage to the hard drive, data can be successfully recovered by specialist tools and replacement of faulty parts or updating the firmware located in the system area of the hard drive.

Physical damage

A wide variety of failures can cause physical damage to storage media. CD-ROMs can have their metallic substrate or dye layer scratched off; hard disks can suffer any of several mechanical or electronic failures, such as head crashes and failed motors; tapes can simply break. Physical damage always causes at least some data loss, and in many cases the logical structures of the file system are damaged as well. This causes logical damage that must be dealt with before any files can be rescued from the failed media.

Physical or severe logical damage to storage media cannot be repaired by end users therefore professional help must be sought. For example, opening a hard disk in a normal environment, can allow dust and damaging particles to settle on the surface of platters, causing further damage to them and complicating the recovery process. Furthermore, end users do not have the hardware or technical expertise required to make these repairs for the purpose of data recovery; therefore, a data recovery company must be consulted. Professional data recovery companies such as Data Recovery Doctor, have advanced tools and clean room facilities to protect the media while hard drive repairs for data recovery are being made. The extracted raw image can be used to reconstruct usable data after any logical damage has been mended. Data recovery success rates  by Data Recovery Doctor are about 85-99% depending on the complexity of the data recovery.

Logical damage

Far more common than physical damage is logical damage to a file system. Logical damage is primarily caused by power outages that prevent file system structures from being completely written to the storage medium. Other causes of logical damage to the hard drive, include electrostatic discharge (ESD) or "body electricity or finger sparks". This can cause loss of data by corrupting the logical format of the hard drive. Also corrupt device drivers, as well as system crashes, can have the same effect. The result is that the file system is left in an inconsistent state. This can cause a variety of problems, such as strange behaviour (e.g., infinitely recursing directories, drives reporting negative amounts of free space), system crashes, blue screens or an actual loss of data.

Data Recovery Doctor possess special tools and  disk editing software which enable their technicians to correct these inconsistencies and therefore recover data from faulty partitions.

Two main techniques are used by data recovery technicians. The first, consistency checking, involves scanning the logical structure of the disk and checking to make sure that it is consistent with its specification. For instance, in most file systems, a directory must have at least two entries: a dot (.) entry that points to itself, and a dot-dot (..) entry that points to its parent. Special tools are used that can read each directory and make sure that these entries exist and point to the correct directories.

The second technique for file system repair is to assume very little about the state of the file system to be analyzed, and using any hints that any undamaged file system structures might provide, rebuild the file system from scratch. This strategy involves scanning the entire drive and making note of all file system structures and possible file boundaries, then trying to match what was located to the specifications of a working file system.

Data Recovery Doctor can recover data even when the logical structures are almost completely destroyed. This technique generally does not repair the underlying file system, but allows the data to be extracted to another storage device successfully.

The increased use of journaling file systems, such as NTFS 5.0, ext3, and XFS, is likely to reduce the incidence of logical damage. These file systems can always be "rolled back" to a consistent state, which means that the only data likely to be lost is what was in the drive's cache at the time of the system failure. However, regular system maintenance should still include the use of a consistency checker. This can protect both against bugs in the file system software and latent incompatibilities in the design of the storage hardware.

Firmware Corruption

Some kinds of logical damage can be mistakenly attributed to physical damage. For instance, when a hard drive's read/write head begins to click, most end-users will associate this with internal physical damage. This is not always the case, however. Quite often, either the firmware on the platters or the controller card will instead need to be re-programmed. The firmware is normally located in the system area on the circuitry inside the hard drive and/or on the chip on the print controller board (PCB). Once the corrupt firmware on either of these two devices is restored by using specialist tools, the drive will be back in shape and the data will become  accessible for data recovery.

For more information on data recovery or any data loss situation, please call 0207 516 1077 and speak to a Data Recovery Doctor. 

If require any data recovery services, please call us on 08700 116550. You can also contact us via email: info@datarecoverydoctor.co.uk. If you are looking for other computer services, visit our partner website www.computerdoctor.co.uk or call 0870 8407989.

How to prevent data loss

Data Loss: Why it happens and how to prevent it

There are two major reasons for your data storage device failure:  poor handling and manufacturing defects.

· Poor handling: 
Even if the today's hard drives, for example, are capable of handling operational shock up to 300 G, their electronics or mechanical components still could be damaged by the vibration or by an impact. Liquid spilled on the drive may short electric connections or even penetrate inside the drive, especially inside the drives with removable media (Zip, CD-everything, Tape drives, etc.).  Contamination of the drive's insides by dirty media or the environment could speed up mechanical wear or result in immediate failure. One possible reason for damage to the drive's electronics is an electro-static discharge, a so called ESD, which often happens between your fingers and the drive's body.  During this discharge a large potential can be generated at the very small gaps and in small areas causing heat dissipation, melting and disintegration of the IC elements. This is why most electronics and storage devices are shipped inside a special ESD-protecting plastic bag. When handling the drives, try to keep your other hand on a metal part of your PC such as the frame, which will serve as a "ground".  Also, touch the metal part of your PC with both hands before handling any ESD-sensitive device.

§ Manufacturing defects:
Unfortunately, even those of us who handle things with great care are not immune from disaster. All media, drives and storage system components undergo thorough testing, but in spite of this, statistics guarantees a few bad drives among hundreds of good ones... You may be unlucky and buy one of those.  But even in this case, data back-up and a good manufacturer's warranty can make losses partially or completely recoverable.

How to prevent Data Loss:

· The best prevention is to always remember to back-up your data!
Accidents may happen: coffee is spilled on your CD or Zip drive, a CD falls on the floor and gets scratched, the hard drive does not want to spin after being unused during 2 humid summer months. Anything may happen, but you should not worry if your most valuable data is stored separately in a safe place.

· Another thing to remember is to use anti-virus software routinely, especially if you download from the Internet! Your data could be as easily corrupted by a computer virus as by any natural disaster. To protect your data from the newest viruses, update your antivirus program as often as possible.

· Prevent impacts on your storage device, especially when it is running! For example, don't move your desktop when the power is on! All commercial storage systems are designed to withstand significant shock and vibration, but there is always a chance that your drive may be damaged by an impact.

· Avoid electro-static discharge (ESD) during installation of the drives and later handling.  Do not touch electric contacts on the controller board with your bare hands. When handling the drives, try to keep your other hand on a metal part of your PC, which will serve as a "ground".

· Keep your storage systems clean!
Particulate contamination is a clear and present danger for all types of storage media since is causes mechanical damage which is rarely recoverable and can crash the entire storage device!       

· Keep you data cool!
Storage systems, especially magnetic media, may suffer from the so-called 'thermal decay' of magnetic information. In other words, your magnetic domains will lose their magnetization much faster at higher temperatures, and your bits of information will disappear... Magnetic drives are designed to operate in conditions comfortable for humans. Therefore, there is no danger in keeping your drives at 40c (104F) and even 50c (122F). But, exceeding this temperature by much can be harmful.

· Keep away your magnetic storage from strong magnetic fields (Mobile phones, strong electrical currents, TV sets, magnets etc. 

What to do if you have lost your data? 

Floppy diskettes:

Floppy diskettes are designed to be robust and to operate in an unfriendly environment filled with dirt, abrasive particles, moisture, etc. But, still, the environment and the way we handle floppy disks may result in damage.

Low magnification (X 25) image of the scratch on the floppy disk surface.

· If you cannot read from a new floppy disk, it just may need formatting! But, make sure there is no data on the floppy disk - formatting will definitely erase all the data forever! Nowadays most floppy disks are sold pre-formatted for IBM-type PCs or for the Macintosh. Check if the operating system marked on the floppy box is same as operating system you are using.

· If you can not write to the floppy, check if the switch on the back of the floppy is in write-protect mode. If it is, switch it to another position.

· Next, try to read this floppy using another floppy drive (ask a friend or colleague), maybe the problem is in the drive, not in the floppy.

· Next, slide the metal window on the floppy aside and check the surface for damage. Usually, the surface will appear as a dark mirror, and you can easily see if there is a circumferential scratch on the surface.

· If there is a scratch, you have mechanical damage to your magnetic media. One can rarely recover data from mechanically damaged areas since the magnetic bits may not exist there anymore. But, there is still a chance to recover data on the other parts of the disk. If these data are valuable to you, do not try anything else on your own. Contact Data Recovery Doctor on 08700 115 114.

· If there is no visible scratch, there could be some particle or dirt stuck to the disk surface. It is sometimes helpful to blow air on the disk surface through the open metal window. You may simultaneously gently rotate the disk to treat the entire surface. Be careful, don't spit on the disk accidentally! After you are done, try reading from this floppy again. If it does not work, Data Recovery Doctor on 08700 115 114.

· If your floppy drive won't work, start your CMOS Setup and check the BIOS setting for the floppy drive. If A: (or B:) drive is set as none or not installed, the drive will not work. Change the settings and save them before exiting, if necessary.

· If this does not work, check the cables. Check the power cable for a bad connection, and check the twisted cable for the correct configuration: drive A: should be connected to the end-most connector (after the cable twist) and drive B: to the middle connector (before the twist).

· If this does not help, replace the twisted cable.

· Finally, to make sure that the problem is in the drive, check to see if a different floppy drive will work in the same place.

Zip disks:

Zip and similar products are also designed to be robust and operate in an unfriendly environment filled with dirt, abrasive particles, moisture, etc. Plus, they work at a much higher rotational velocity (~3000 rpm vs. 300 rpm for floppy disks). We, personally, have never experienced Zip disk failure, while dealing with dozens of Zip drives. The enclosure of the Zip disk is less open than that of the floppy. Therefore, there is not much that can be done if it suddenly stops reading or writing.

· First, try to read this Zip disk using another Zip drive (ask a friend or colleague). Maybe the problem is in the drive, not in the Zip disk.

· Blowing air through the opening of the Zip disk may not be a good idea, since the slider / disk interface of the Zip drive is more delicate that that for floppy drives. If the data on the disk are valuable to you, do not try anything else and Data Recovery Doctor on 08700 115 114.

Hard Disk Drives: data loss and recovery

Do not try it at home... Probably the most complex data storage system available.
Typically, magnetic drives are assembled in the clean room conditions to prevent contact interfaces from being exposed to contamination. Since, in a typical room environment there are zillions of particles, opening the disk outside the clean room would, most likely, significantly shorten the drive's life.

Also, do not open the drive since, if it is opened, the warranty will be voided, and you will lose the drive along with the data...

· WARNING!!! Repeated attempts to restart the drive after it has failed to start may cause irreparable damage. Also do not try to recover data from your hard drive by using data recovery software downloaded from the internet. This will further reduce the chances of a proper data recovery!

The first indicator of approaching HDD problem is an increasing frequency of drive-related computer failures, when your PC dies suddenly (which also can be due to bad RAM, bad IDE connector / cable, or other reasons) or shows a diagnostic with one of the many drive error codes. Running Scandisk utility (Windows 95) or any similar program may cure the problem if the bad bits, which the program will mark, do not grow in size or migrate with time. If use of Disk Utilities does not solve your drive's problem, you may start thinking about backing-up you data and contacting the drive manufacturer to ask for a replacement drive. 

Sound can be used to evaluate the drive's condition. Unless your drive is in a sleep mode (power saving mode), you can hear the spindle sound. Press the "save" button in any application and you will hear the sound of the voice-coil actuator (VCA) moving the head to the required LBA.   If your drive makes no sound at all, this may indicate a simple bad connection of your power cable, or a more serious (but mostly reparable by the expert) problem with the drive's electronics, when the motor can not overcome static friction between the disks and the heads in the drive. The problem may occur if you have not used your drive for a while, and this problem is exacerbated by high humidity.

Finally, no sound or a weird rubbing sound may indicate a head crash which is usually associated with damage to the magnetic media and partial data loss.

Data loss in hard drives can also occur by any or a combination of the following factors:

•  File System Corruption  Driver Corruption
• Broken Master Boot Record
•  Virus Attack
• Spyware
• Hardware Conflicts

Optical Drive Data Recovery: CDs, DVDs, CD-R, CD-RW:

If you have problems with reading the CD, it's mirror surface could be contaminated by particles, fingerprints, various stains or, unfortunately, scratched.

· To clean your CD use a soft lint-free cloth and apply light strokes in the radial direction only! The data on CDs are stored and read in a circumferential direction and the drive's optic is less sensitive to radial scratches you may generate yourself!

Data on CD disks is protected by a layer of lacquer on one side (mirror side) and by another layer of polycarbonate (PC) plastic on the other side (label side).  The data are stored in the form of shallow pits in the PC matrix covered with a thin reflective layer of aluminum.  If you scratch the disk and this scratch is deep enough to damage (remove) the pits, your data is lost locally. Fortunately, CDs are robust and not all scratches cause irreversible damage.  Try polishing shallow scratches away with mild abrasives (i.e., toothpaste or furniture polish). Clean away the residue. Use radial strokes only!

· Try to use fillers for deeper scratches (furniture wax, car wax, etc.).  Cover the entire surface and buff out using clean cloth. Again, use radial strokes only!

Try to copy or duplicate the damaged CD as soon as possible.

· WARNING!!! Damage to the label side of the CD could be even more dangerous than to the mirror side.

In case of data loss or damage to your storage media or drive, do not panic and do not try to fix the problem immediately - you may destroy your last hope yourself (for example, by repeatedly restarting your hard drive hoping that it will finally boot-up in spite of that squeaky sound coming from the inside...SEEK PROFESSIONAL HELP!).

If require any data recovery services, please call us on 08700 116550. You can also contact us via email: info@datarecoverydoctor.co.uk. If you are looking for other computer services, visit our partner website www.computerdoctor.co.uk or call 0870 8407989.

About Data Recovery Doctor

• Telephone: 0845 257 9165
• Fax: 0207 117 4263
• Email: info@datarecoverydoctor.co.uk
• Address and drop-off location:
• 100 Kingsway, No 611 , Finchley, London N12 0EQ (100 Kingsway is a tall white new building where we are. When you are in the reception, call or text 07876543212. Our workshop is on the six floor and a technician will meet you at the reception once we know you are there.)
• Directions: We are located in North Finchley, London. The closest tube station is Woodside Park (SEE MAP) but one easy way to come to us is to travel to Finchley Central Tube Station on the Northern Line, then take ANY double-decker bus (460, 125 or 82) bound for Tally Ho from the bus stop in front of Tesco in Ballards Lane. Then you have to get off in Tally Ho (WATCH OUT THE WHITE TALL BUILDING BEFORE YOU GET OFF; YOU CAN'T MISS THE TALLY HO BUILDING, ALSO KNOWN AS 100 KINGSWAY. If you are on bus number 82, the last stop will be just in front of the TALLY HO BUILDING i.e 100 KINGSWAY or tall white building. To see a map of our location, click here.
• OPENING TIMES: Mon-Thurs 9am-9pm; Friday 9am-630pm; Saturday 10am-630pm (Please note the building reception is 24/7. If you have to come to us outside office hours for an emergency, please call or text 07876543212 in advance and say when you will be there approximately. Also you can call or text 07876543212 and say you are at the reception and a technician will come down to see you.)

Data Recovery Tips

First of all, don't panic. Data loss is very common, but in nearly all cases, the data can be recovered by a trained technician. Only in the most severe cases of platter damage, magnetic degradation or a file over-write will the data be labelled as unrecoverable. With over 10 years of data recovery experience DRD has seen nearly every scenario of data loss and our successful rate of recovery speaks for itself.

Here are a few tips to help you minimize further data loss and increase your likelihood of data recovery on some of the more common types of data loss:

1. If your system has "crashed" and you can no longer access the operating system or see the drive in the BIOS, then shut the system down immediately and do not run any further power through the drive by attempting reboots. This is considered a physical problem with the drive and is an extremely sensitive issue. If the headstack inside your drive has been damaged, you may cause further additional damage to the platter/s of the drive, upon which your data is stored. Contact a DRD representative and describe your problem.

2. If you have deleted a file or files or accidentally formatted your drive, then the most important thing to remember is to NOT write or install ANY new information onto that drive. Deleting files simply removes the locating tag of the file, but the file is still intact on the drive. If you add new data to the drive, you may over-write your lost data; losing it forever. Using advanced software, DRD technicians can re-assemble the binary code and restore your files.

3. If your partition has become corrupted, the most important thing to remember is NOT to attempt a re-install of your operating system or add new data to the drive. Again, DRD technicians can use specialized software and techniques to repair the partition and/or extract your data.

4. If you have deleted a partition, do not attempt to restore it by formatting the drive as this will only result in the addition of an empty partition. It will not recover your data.

5. If you believe you have been infected with a virus, shut the system down and contact a DRD technician. We may be able to help you identify the threat it poses to your data.

6. If you experience a single file corruption, be sure not to attempt creating a new file with the same name as this will partially over-write the file and will greatly decrease our ability to recover fully.

Remember, these are just a few of the more common reasons for data loss. Any attempts that you or even an IT technician make to recover the file or drive may result in a decreased quality of our recovery efforts or even make it impossible for us to recover the data. If you have any doubt, just ask yourself this question. "Am I prepared to move on without that data?". If you answered no, then contact a DRD representative by phone or email before making any attempts at a recovery. Data recovery is a highly specialized branch of computer science and should be left to those with experience and training to complete it successfully.

Laptop and notebook drives are much smaller and more fragile than their desktop cousins, consequently they require a more delicate and exacting touch to repair and recover. However, the steps listed above for what you, the user, can do to minimize further data loss remains basically the same, with the exception of:

1. Unless the drive was designed to be removed by simply sliding out of the casing, do not attempt to remove it yourself.

2. If you can remove the drive easily, be sure not to put any undue stress on it by applying pressure to the housing on the drive.

3. Take extra care when packaging a laptop drive for shipping, so as not to incur any further damage before reaching one of our labs.

4. In the majority of cases, we will collect your laptop and then we will remove the hard drive ourselves in order to recover data. A DRD technician will be the best person to advise you on what is best to do.

If require any data recovery services, please call us on 08700 116550. You can also contact us via email: info@datarecoverydoctor.co.uk. If you are looking for other computer services, visit our partner website www.computerdoctor.co.uk or call 0870 8407989.

What can we do for you?

Data Recovery Doctor can recover data from all types of hard drives in any of the following conditions:

• The hard drive has been formatted or fdisked;
• The hard drive makes clicking noises;
• The hard drive is inaccessible;
• The primary or secondary hard disk has failed and the system BIOS displays the message "Primary hard disk failure" or "Secondary hard disk failure";
• The system displays the error message "boot disk error, insert boot disk press any key to continue";
• System displays the message "NTLDR is missing, Press any key to restart"
  The hard drive has a corrupt or damaged partition table;
• The hard drive has become inaccessible due to virus attack or virus infection;
  The hard drive is no longer recognized by the BIOS after rebooting, despite the platters spinning;
• The system displays the message "Operating system not found" or "missing operating system";
• The BIOS recognizes the hard drive but with garbage parameters;
• The BIOS recognises the hard drive but the data is inaccessible;
• Hard drive makes grinding or clicking noises, normally associated with electro-mechanical failure;
• The hard drive reports bad sectors;

If require our services, please call us on 0845 257 9165. You can also contact us via email: info@datarecoverydoctor.co.uk.