Not rocket science, it's very easy to figure out. If the hard drive is showing any of the following behavior then it could be imminent indication of Hard disk failure:

• The hard disk is undetectable or not recognized at all by the system.
• The system fails to boot or hang in mid of the booting process. 
• System BIOS is unable to detect the hard drive.
• Hard Drive isn’t spinning.
• Clicking sound or unnecessary noise is arising from the system hardware.
• Files mysteriously disappear. Usually more than once
• Locking up during the boot process - hard disk problems are indicated if this happens frequently
• The computer often freezes, and when it does you are left without mouse or keyboard input and have to do a hard reset
• Standard file processes like saving and opening slow down interminably, even for small files
• Increase in the number of bad sectors noted when running “chkdsk” command
• You can't speed up computer performance even by applying optimization tricks
• You notice that your computer is unusually hot.
• Your computer is bumped or jostled while it is running;
• The electric motor which allows the platter to spin fails due to bad bearings or other components;
• The filter on your air intake gets too clogged or the filter isn't working properly;
• Extreme heat while running causes the electronic circuit board to fail;
• There is a sudden power failure while the disk is writing.

Hard disk failure is most common cause of data loss. Over the years, we at Stellar Data Recovery India have noticed that around 70% of data recovery jobs which we receive are related to HDD only. This is common with domestic and corporate users.

There could be many possible reasons for disk failure; like computer systems are being used more frequently and data is stored continuously. Other factors such as increase in data density and number of platters may also be contributing factors for hard drive failures.

It is documented that 60% of the Hard disk failure occurs because of mechanical failure and the rest 40% occurs through misuse.

Physical Hard Disk failure: - As the name suggests any kind of physical damage to the hard disk like dropping, burning of hard drive can make device nonfunctional. A physical case may appear if:

• Computer not detecting the Hard disk
• Drive not spinning (no power)
• An excessively hot drive
• An abnormal ticking noise whilst the drive is reading data
• A loud clicking or grinding noise

A physically damaged hard disk failure can be easily noticed by looking into a hard drive. In case of a physically damaged hard disk, you may not recover data with the help of any data unauthorized recovery software. Also don't try to open the hard disk by yourself, it may damage your drive further, and you may lose your data permanently.

In case none of the above problems are shown by your HDD, it could be a case of logical failure.

Logical Hard disk Failure: - The damage/ failure occurs in the hard drives file structure or software or malware infections, human error or corrupted files or the hard drive does not boot up.  A logical hard disk failure may appear if:

• Computer Bios see hard disk drive but the data is not accessible
• Defective media/ bad platter
• Data corruption from other file source
• Human errors for E.g. modification in the registry files of the system, alteration in files' attributes of the system and many more can lead to logical damage of the Hard disk drive.

Logical Hard disk failure does not require opening the Hard disk drive; one can use Hard drive recovery software's to get the data. But it is important to analyze the type of logical failure before one attempts to recover data, hence experts' advice is essential and seek experienced HDD data retrieval services.

You can contact us or call us at 1800 -102-3232 to discuss your logical disk failure case. Using any untrusted software can harm your hard disk further, or it could also lock your data, which might be very difficult to recover.

If you think your hard disk drive hasn't encountered a physical or logical failure, then the reason could be electronic/mechanical hard disk failure.

Electronic/Mechanical hard disk failure: - Electronic/Mechanical failure is related to components of the Hard drive goes faulty, and the drive will not be accessed to store data.

An electronic/mechanical hard disk failure may appear if

• Hard disk head or heads crash
• Hard drive motor failure
• Damage of magnetic platters
• PCB damage

Out of the errors mentioned Electronic/Mechanical hard disk failure is complicated and often encompasses logical, electronic or firmware failure. Hence, it takes lot of effort and time, for hard disk data retrieval process, and such cases are treated in Clean Rooms only by Data recovery experts.

Bad sectors are the areas of hard disk that are either inaccessible or un-writeable. The bad sectors can occur due to physical damage to the surface, software error, manufacturing defect or regular wear and tear etc. HDD with small bad sectors can work fine but it's advisable to replace the hard drive if there are large numbers of bad sectors on the hard disk drive because it can lead to hard disk failure and data loss. It's recommended to regularly monitor the status of the HDD with disk monitoring utility like S.M.A.R.T. Even if the hard drive is functioning properly, a small cluster of a bad sector can corrupt data and be the reason for data loss.

When the system gets notifications of bad sector, it marks the sector as bad and ignores it. The sector will be remapped and the reads and writes to that sector will go elsewhere. In case if the data is on these bad sectors then the chances of losing data becomes high. Hence, it is advisable to take regular backup of the data and also to consult a data recovery professional to recover data from bad sectors.

Hard disks are extremely fragile and dropping hard disk can be fatal, dropping the hard disk can damage to its parts like the platters, read/write arm, spindle and other component. This leads to physical damage to HDD and data stored on it becomes inaccessible. To recover data from physically damaged hard disk, it has to be opened in Class Clean Room Labs. Class 100 Clean Room Labs have controlled environment that is suitable for Hard drive, the lab has less than 100 dust particle of size 0.5 microns per cubic foot as compared to 500000 to 1000000 particles in the normal air.

In case of physical hard drive damage its always recommended to visit or seek professional data recovery services to regain data.

Note: Never open hard disk on your own, it can lead to permanent data loss.

Crashed hard disk means that its internal component like read-write head, platters, spindle etc. have been damaged. There can be many reasons which are categorized as, logical crash, logical cum physical crash and physical crash. For logical error download Stellar Data Recovery software, to recover data. But in the case of physical crash or logical cum physical crash, the data can be recovered only by professional data recovery experts.

Try the following methods

• Shut down the system and restart again: sometimes simply restarting operating system resolves the issue.
• Uninstall and reconnect the device:
  • Click on Start and type Device Manager
  • Click on Device manager, check the USB drive on the list of hardware mentioned.
  • Uninstall the device.
  • Reconnect the device after installing, it will load automatically.
• Change drive letter name(C drive, E Drive etc.) from disk management
• Boot into safe mode and see if you can access the drive. If so, you've any malicious programs installed that conflicting with drive accessibility.
• Reinstall USB controllers
  • Click start and type device manager
  • Click on Device Manager
  • Click on Universal Serial bus controllers and uninstall the device in question.
  • Restart the system. The USB controllers will be automatically installed.

If all the above-mentioned methods do not help and the drive is still not recognized. Visit data recovery professional to regain/ retrieve data.

Numerous reasons can cause "Drive not accessible, access is denied".

• Power failure for powered hard drive
• Plug in and Plug out the external hard drive improperly
• Virus attack
• File system goes wrong, such as DBR, MFT, FAT.
• The device is physically damaged

The error message is an indication of a problem with the hard disk drive, which has led to inaccessibility of drive. In worst case scenario it can lead to data loss, to avoid such squabble we recommend using Stellar Data Recovery Software.

The external hard drives are mechanical devices unknown to common users, it has small components that make it functional. Even a slight error in the components can halt the function of the hard disk. So when the hard drives may become undetectable, it can be due to

• After sudden power surges while they're being used to transfer data
• If they suffer physical damage resulting from mishandling or dropping
• Due to abrupt system termination while they're connected
• Due to virus/malware infection
• Owing to wear and tear on the hard drive due to overuse
• Deletion of hard drive system files or OS corruption

When the hard drive isn't detected by the system, the user can experience, No sounds, no Auto play or it may disappear from the Device Manager. No need to panic here is quick fix for this problem

• Try plugging the hard drive into different USB Port. The USB port may be faulty due to which the HDD was not connected.
• Connect the Hard disk to another system or laptop.
• Reassign the drive letter

While trying the last option, you may get a prompt asking to format the drive. Please do not panic and make sure you don't lose data before formatting.

This is a very common problem; the users need to make sure that they do not use the hard disk drive that has been formatted. All the previous files on the HDDmight be overwritten by the new files, making data recovery impossible. We recommend using reliable and licensed software, Try Stellar Windows Data Recovery Pro.