A disk rarely fails all at once. First, a file copy freezes. Then a document only opens on the third try. Sometimes a quiet clicking sound appears that wasn’t there before. And one morning, the disk isn’t recognized by the computer at all.
When it holds the only copies of your photos, invoices, or ongoing work, it’s nerve-wracking. The bad news is that every further attempt to “get it working somehow” can permanently damage the data. The good news is that a large percentage of cases can be recovered — if the disk is powered off in time and placed in the right hands.
An immediate answer: If the disk is clicking, grinding, or is no longer recognized, turn off the computer and stop using it. Do not run repair tools or copy data back and forth — with a mechanical failure, every minute of operation risks further damage. If you have accidentally deleted files or formatted a partition, the most important thing is to stop writing anything to the disk. The rest will be determined by diagnostics: the type of damage, the realistic chance, and an estimated price.
Why data suddenly becomes unavailable
A disk rarely goes dark without warning. Before it stops, it gives signs — and those who notice them in time have a much greater chance of saving their data.
A physical failure announces itself with sound and behavior: regular clicking, grinding, or repeated spinning up and spinning down of the platters. In the system, this manifests as freezing when opening a certain folder, suddenly slow copying, or read error messages. When reading only stutters in places, it could be bad sectors that are spreading — another reason to power off the disk and back it up as soon as possible.
The second common cause is not a malfunction, but one hasty step: deleted files or a reformatted partition. A simple rule applies here — the less you do with the disk after the mistake, the better. Every write operation can overwrite the very data you want back.
What to do immediately (and what not to do)
The first few minutes matter more to the outcome than anything later.
- Turn off the computer. For a disk making unusual sounds, don’t test “if it will catch again.” Every extra spin wears out an already damaged mechanism.
- Do not use repair utilities. CHKDSK, “disk repair” in Windows, or similar tools can finish off a damaged disk instead of repairing it.
- Do not copy data back and forth and do not install recovery programs on the same disk. For deleted files, this overwrites exactly what can still be saved.
- Do not disassemble the disk. Opening a hard drive outside a cleanroom environment practically spells the end — a single dust particle between the head and the platter is enough.
- Forget the “home tricks.” Neither a freezer nor tapping the disk fixes anything; these are myths that only deepen the damage.
If the disk is encrypted (for instance, with BitLocker), have your recovery key ready. Without it, the data will remain unreadable even after a successful physical repair — more in the article what is BitLocker.
How professional data recovery works
The procedure depends on whether it’s a logical or physical failure.
For logical failures — a deleted partition, a damaged file system, reformatting — we work with specialized software through a hardware write blocker. This physically prevents any writing to the original disk, so we read from a secure copy, and the original remains unchanged.
For mechanical damage — a clicking disk, a seized motor, faulty read/write heads — the disk is opened in a cleanroom box. Replacing the heads, repairing the electronics, or replacing other compatible parts depends on the specific fault and requires an identical donor model and precise manual work. This cannot be done on an office desk, and it is not an on-the-spot job.
When recovery makes sense and when it doesn’t
Not everything can be saved at a reasonable cost. The type and extent of the damage are the deciding factors. Consider the following scenarios as a guide:
| Disk Condition | Chance of Recovery | Note |
|---|---|---|
| Deleted files, disk otherwise healthy | High | Stop using the disk immediately |
| Reformatted partition with no further overwrites | High | Recovery of file structure |
| Damaged electronics (e.g., burnt TVS diode) | High | PCB repair/replacement, ROM transfer |
| Faulty read/write heads, platters intact | Medium | Cleanroom box and donor disk required |
| Scratched platters after a head crash | Low to none | Damaged magnetic layer |
| Data repeatedly overwritten by new data | Zero | Data is permanently gone |
For SSDs, it’s different. The TRIM function, which maintains write speed, releases and gradually erases cells after a file is deleted — and once erased, data from an SSD generally cannot be recovered from anything. The more time that has passed since deletion or formatting, the lower the chance. When an SSD controller fails, recovery is technically more demanding and typically more expensive than with a standard platter-based drive.
What is the approximate cost of data recovery in Brno
The price is determined by three things: the type of damage, the disk capacity, and how quickly you need the data. A specific amount can only be given after diagnostics — a “ballpark” flat rate makes no sense for data recovery. The type of case roughly influences the cost:
- Logical failure (deleted files, format, corrupted partition table): the technically simplest operation; the price usually includes the media for returning the recovered data.
- Mechanical damage (replacing read/write heads, repairing electronics, replacing compatible parts): the price is increased by cleanroom work and sourcing donor parts. The cost rises for rarer models where finding a donor is difficult.
- SSD: the price is determined by the type of failure and the controller complexity.
- RAID and NAS: the price is mainly determined by the number of disks and the array type.
Priority processing is usually subject to a surcharge. We perform diagnostics before we begin any work — we state the result and estimated price upfront and do not proceed without your approval.
How to tell a quality service from a garage operation
The demand for data recovery also attracts people without the proper equipment. You can recognize a reputable service by a few things:
- Diagnostics before price. An honest technician will not quote a price without seeing the disk. Each case is different, and a “ballpark” flat rate is either a deception or a signal that no one will tackle anything complex.
- Equipment. Any mechanical intervention into a disk belongs in a cleanroom environment (laminar flow bench, cleanroom). Without it, heads are changed blindly with a minimal chance of success.
- Write blockers. For logical recovery, a hardware write blocker is a necessity. Software protection is not enough.
- Transparency. You should know what will happen and, before taking delivery, receive a list of the recovered data. “We saved what we could” without proof is insufficient.
RAID and NAS: when more than one disk fails
Corporate data often doesn’t reside on a single disk but on a NAS or server with a RAID array. Paradoxically, this may not help: a controller error, a power outage, or a bad configuration change can make the entire array inaccessible, even if the disks themselves are mechanically fine.
Recovery from RAID and NAS is its own discipline. It requires knowledge of the file systems used (ext4, Btrfs, XFS, and NAS manufacturer formats) and, without a functional controller, the ability to calculate the array parameters — disk order, stripe size, and parity rotation method. The chance of success is usually high if only the array failed, not multiple disks mechanically at once. This is discussed in detail in a separate article on RAID and NAS data recovery.
Corporate data, backups, and obligations
Data loss in a company is not just an operational problem. When it involves the personal data of employees or customers, it can also become a legal obligation. Under GDPR, a serious leak or loss of personal data must be reported to the supervisory authority, usually within 72 hours of discovery.
In addition, stricter cybersecurity rules apply to organizations in certain sectors and of a certain size — the Czech Cyber Security Act and the European NIS2 directive. They don’t apply to every small business, but those they do apply to have their own reporting obligations (in the Czech Republic, to NÚKIB); what this means in practice is summarized in the article about the Cyber Security Act and NIS2.
The cheapest data recovery is the one you don’t need. However, a backup to the cloud or an external drive is not a cure-all until you verify it regularly — restoring from a three-month-old backup means three months of work are lost. A reasonable minimum is to have data in multiple places, one copy off-site, and a periodic test restore to see if the backup actually works.
Do you have an unreadable disk right now?
The best thing you can do for your data is to leave the disk alone and send us the model and a description of what happened — whether it’s clicking, no longer recognized, or you deleted a partition. Based on that, we will tell you what is likely, what will be tested, and an estimated price before we proceed with anything further.