Data Recovery from Hard Disks: Frequently Asked Questions

A practical customer guide to hard-disk data recovery.

This FAQ answers the questions most often asked after data becomes inaccessible on a hard disk drive (HDD). It explains the safest immediate action, what affects recoverability, and what to expect from KAOS Data’s assessment and recovery process. Detailed technical and preventative guidance is linked under Related guidance.

IMPORTANT: If a hard disk is clicking, grinding, scraping, repeatedly spinning up and down, has been dropped, or is no longer detected, stop using it and power it off. Do not keep testing or restarting it. Continued operation can worsen physical damage and reduce the chance of recovery.

Why Data Recovery May Be Required

Data recovery becomes necessary when data is lost, corrupted, or inaccessible. Common causes include:

Physical Damage

Dropped or impacted drives – Mechanical components (read/write heads, platters) are extremely sensitive.
Liquid damage – Water, coffee, or other liquids can short electronics or cause corrosion.
Overheating or fire damage – Excessive heat can warp platters or damage circuitry.
Wear and tear – HDDs contain moving parts that degrade over time.

Logical Damage

Accidental deletion – Files or folders deleted unintentionally.
Formatting errors – A disk or partition formatted by mistake.
File system corruption – Power loss or improper shutdowns damaging file structures.
Software bugs – Faulty applications or operating systems corrupting data.

Electrical or Electronic Failure

Power surges – Can destroy the drive’s controller board.
Faulty power supplies or cables – Causing sudden shutdowns or voltage spikes.

Malware and Cyber Incidents

Ransomware – Encrypts files and blocks access.
Viruses or malicious software – Deleting or corrupting data.

Human Error

Incorrect system configuration
Overwriting important data
Improper handling or storage of drives

Methods Used to Recover Data

The recovery method depends on the type and severity of the failure. Each of these methods require the appropriate tools and skills necessary to use those tools.

Software-Based Recovery

Used mainly for logical issues.

File recovery tools to restore deleted files
Partition recovery utilities
File system repair tools

Best suited for: Accidental deletion, formatting, minor corruption.

Hardware-Based Recovery

Used when physical or electronic components fail.

Replacing or repairing controller boards
Repairing damaged connectors
Transplanting components (e.g., heads or platters)

Best suited for: Drives not detected, electronic failure, physical damage.

Clean Room Recovery

Performed in specialized dust-free environments.

Opening the drive safely
Repairing or replacing internal components
Imaging platters to extract raw data

Best suited for: Severe physical damage, head crashes, dropped drives.

Data Reconstruction

Rebuilding corrupted file systems
Reassembling fragmented or partially damaged files

Best suited for: Severe logical corruption or incomplete data sets.

1. What to do immediately

What should I do first when data is lost or inaccessible?

Stop using the affected device. Continued use can overwrite deleted data or place additional stress on a failing drive.

If the drive is operating normally and the problem appears to be accidental deletion, do not save files, install software or run repair utilities on that drive. Check your backups before taking further action.

If the drive has been dropped, is making abnormal noises, is repeatedly disconnecting or is not detected, shut the system down and leave the drive powered off.

What should I avoid?

Do not repeatedly reboot the computer or power-cycle the drive.
Do not initialise, format, repartition or erase the affected device.
Do not run repair utilities or long diagnostic scans when the data is important.
Do not install recovery software on the affected drive or save recovered files back to it.
Do not open, freeze, tap, shake or attempt to swap internal components.

Any action that changes or further stresses the source device can reduce the remaining recovery options.

My hard disk is making unusual noises. What should I do?

Repeated clicking, grinding, scraping, loud buzzing or repeated spin-up and spin-down is a physical warning. Power the drive off immediately. Do not continue running tests or leave it powered merely to identify or record the sound.

For a detailed explanation, see Hard Disk Making Noises? Here’s What to Do.

My drive is not detected. Can I keep reconnecting it?

If there are no abnormal noises and the device has not suffered an impact, liquid exposure or power event, one controlled check with a known-good cable, port and correct power supply may be reasonable. If the drive remains absent, behaves intermittently or makes unusual sounds, stop. Repeated power cycles can make some faults worse.

2. Recovery prospects and do-it-yourself options

Can my data be recovered?

Often, but not always. Recoverability depends on the type of failure, the extent of any physical damage, whether data has been overwritten, encryption, the condition of the storage surface and what has been attempted since the problem began. Early, non-destructive action generally preserves more options.

Damage to areas of the platters can make data stored in those locations permanently unreadable, although files stored elsewhere may still be recoverable.

What is the difference between a logical failure and a physical failure?

A logical failure occurs when the storage medium can still be read but files, partitions or file-system records are deleted or damaged. A physical failure involves the electronics, motor, read/write heads, bearings, platters or other hardware. Physical symptoms require controlled assessment and may require cleanroom work.

Is data recovery guaranteed?

No. A professional assessment identifies the likely failure and the safest recovery path, but no provider can guarantee recoverability before the media has been inspected and imaging has begun.

What recovery success rate does KAOS Data report?

KAOS Data currently reports an overall recovery success rate of approximately 90 percent. This is an aggregate figure across past recovery attempts and is not a guarantee for any individual drive, folder or file.

Can I recover the data myself?

Sometimes. A healthy drive affected by a recent deletion or minor logical issue may be suitable for software-based recovery. However, recovery software can place a heavy read load on a weak drive and can overwrite data if it is installed on the source or if recovered files are saved back to it.

For important or irreplaceable data, obtain advice before scanning. Professional practice is to preserve the original device and work from a controlled sector-level image whenever possible.

Should I use free recovery software?

Price alone does not determine whether a recovery tool is suitable. The important questions are whether the drive is physically healthy, whether the tool writes to the source, whether it supports the file system, and whether recovery can be performed from an image rather than the original device. Do not use software on a clicking, grinding, unstable or repeatedly disconnecting drive.

Can I open the hard disk or replace parts myself?

No. Opening a mechanical hard disk outside a suitable cleanroom can contaminate the platters and cause additional damage. Internal parts are model- and revision-specific, and modern drives often require specialist hardware, firmware knowledge and calibration. Leave the drive sealed.

When is cleanroom recovery required?

Cleanroom work may be required when internal mechanical components have failed, for example after a head crash, seized spindle, contamination or impact damage. The objective is not to return the drive to normal service; it is to stabilise the device long enough to create a readable image.

3. Assessment, pricing and timing

What are the current service terms at a glance?

Item	Current published approach
Initial assessment and quotation	Free
Typical assessment time	Usually 24 to 48 hours after the device is received
Quotation	Fixed quotation, with approval required before chargeable recovery work begins
Recovery charge	No data, no recovery charge
Typical published price range	AUD $200 to $1,800, depending on the fault and work required
Priority service	Available at additional cost, subject to workload and device condition
Freight and destination media	Additional where applicable

Do you need to inspect the drive before quoting?

Yes. Symptoms alone cannot reliably distinguish cable, electronics, firmware, head, motor, media or logical faults. Assessment allows KAOS Data to identify the likely failure, determine whether parts or cleanroom work may be required, and provide a fixed quotation.

Is the assessment and quotation free?

Yes. The current published service offers a free assessment and quotation. Chargeable recovery work does not begin until the quotation is approved.

How long does the assessment take?

Assessment is normally completed within 24 to 48 hours after the device is received. Complex or intermittent faults may take longer.

How much does data recovery cost?

Current published pricing indicates that many recoveries fall between AUD $200 and $1,800. The final price depends on the fault, drive type and age, parts required, prior recovery attempts, and the time involved. A fixed quotation is provided after assessment.

Freight, return shipping and a replacement device for recovered data are separate where applicable.

Do you charge according to the amount of data recovered?

No. The recovery charge is based on the complexity and work required, not simply on the number of gigabytes recovered.

What happens if no data is recovered?

Under the current ‘no data, no charge’ approach, there is no recovery labour charge if data cannot be recovered. Shipping, return freight and any requested replacement media may still be payable.

How long does data recovery take?

A simple logical recovery may take hours. A physically damaged drive can take several days or longer, particularly if donor parts are required or the drive must be read slowly around unstable areas. Large-capacity drives also take time to image and validate.

Because each drive behaves differently, an exact completion time may not be possible until assessment and initial imaging have begun.

Can an urgent recovery be prioritised?

Yes. Priority service is available at additional cost, subject to current workload and the condition of the device. Priority changes queue position; it cannot make an unstable drive safely read faster than its condition allows.

4. The recovery process and your returned data

What happens during professional data recovery?

The device is assessed and its condition is documented.
Where necessary, the drive is stabilised or repaired only enough to make safe reading possible.
Readable sectors are copied to controlled working media so the original device is exposed to as little further stress as possible.
Files and file-system structures are reconstructed from the image.
Recovered data is validated as far as practical and copied to a separate healthy destination device.

Will the original drive be repaired for continued use?

No. Any repair or component replacement is performed solely to make the drive readable long enough to recover data. A failed drive should not be returned to production or trusted as a backup device.

How will I receive the recovered data?

Recovered data is copied to a healthy destination drive. You may provide a suitable device or ask KAOS Data to supply one. The required capacity and interface can be confirmed after assessment.

Will the original filenames and folder structure be preserved?

When file-system metadata remains intact, the original names and folders can often be preserved. If metadata is badly damaged, files may need to be recovered by type or signature, which can result in generic filenames, lost folder paths or partial files.

Can some files be damaged even when the recovery succeeds?

Yes. A successful recovery may still contain files that were stored in unreadable sectors or were already corrupted. The outcome should be assessed by the important files that can be opened and used, not only by the total volume recovered.

5. Devices, encryption and confidentiality

What types of devices can KAOS Data assess?

Mechanical hard disk drives are the most common devices submitted. KAOS Data also assesses some solid-state drives, USB storage devices, memory cards and tape. Recoverability varies significantly by device, controller, firmware, encryption and type of damage. Contact KAOS Data before sending unusual or legacy media.

Can encrypted data be recovered?

Recovery may restore encrypted sectors, but usable files still require the correct password, recovery key or encryption keys. If those keys are unavailable, recovered data may remain unreadable. Do not send credentials with the drive unless a secure method has been agreed in advance.

What should I do after a ransomware incident?

Disconnect the affected system from networks and stop normal use. Do not assume that disk recovery alone will resolve ransomware: the response may also require incident containment, forensic preservation, clean systems, backup validation and assessment of available keys or decryptors. Obtain specialist advice before making changes to the affected media.

Will my data remain confidential?

KAOS Data handles personal information under its published Privacy Policy. Before sending media, advise KAOS Data of any legal, regulatory, non-disclosure, data-residency, retention or secure-destruction requirements so they can be agreed in advance.

6. Sending a drive and contacting KAOS Data

Where is the recovery facility?

The data recovery facility and cleanroom are based in Sydney, Australia. Devices can be shipped from other locations by prior arrangement.

How should I package a drive for transport?

Keep the drive powered off and sealed. Place a bare drive in an anti-static bag if one is available.
Wrap the device in bubble wrap or protective foam, then use a strong outer box packed so the device cannot move. Avoid loose material that can enter connectors or ventilation openings.
For an external drive, include the enclosure and power supply only if requested.

Contact KAOS Data before shipping so the device and return details can be identified correctly. Use a tracked shipping service and retain the tracking details.

What information should I provide with the device?

Information	What to include
Device	Make, model, capacity and serial number, if available
Failure event	For example: drop, liquid exposure, power event, deletion, formatting or sudden failure
Symptoms	Noises, error messages, intermittent behaviour and whether the device is detected
Computer or system	Windows, macOS, Linux, NAS, server or RAID; file system if known
Previous attempts	Software scans, repairs, component changes or whether the drive has been opened
Encryption	Encryption type and whether the password or recovery keys are available
Priority data	The folders, file types or records that matter most, plus any genuine deadline
Contact and return details	Name, phone, email, return address and preferred contact times

Accurate information about earlier attempts is important because it affects the safest recovery plan.

Do you have a phone number, and what is the best way to contact you?

Yes. The preferred first step is the online Contact Us form. Include your phone number, a brief description of the problem and your preferred contact times. A team member can reply or call you back. This allows the symptoms to be reviewed before further action is recommended.

What happens after I contact KAOS Data?

KAOS Data will review the symptoms, advise whether the device should remain powered off, and confirm what to send and how to ship it. After assessment, you receive a fixed quotation and can approve or decline the work. If the quotation is declined, return arrangements can be made; return freight applies.

Related guidance

For more detailed guidance, see:

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Data Recovery from Hard Disks and Frequently Asked Questions