Data Recovery: When data can be saved and what not to do

Two completely different phone calls about lost data come into the service center. The first: “I accidentally deleted an entire folder of photos, emptied the Recycle Bin — is it gone forever?” And the second: “The drive started making a weird clicking sound and I have absolutely everything on it.”

They sound equally desperate, but they’re two opposite worlds. The first case usually isn’t as bad as it looks — data can typically be recovered if you don’t make a rash mistake. The second is a race against time, where one wrong reaction decides whether the data can still be saved. This article is about how to tell which of those two worlds you’re in, and what (not) to do.

Rule #1, before you start dealing with anything: if the drive clicks, beeps, screeches, or disappears and reappears and it holds valuable data — shut it down and don’t touch it. Every additional power-up further destroys a dying drive. Conversely: a deleted file on a healthy drive isn’t going anywhere until you start writing to the drive. Calm is your best tool here.

First, figure out what kind of loss you’re dealing with

This is the whole fork in the road. Whether the data can be recovered, and how, doesn’t depend on panic, but on what exactly happened.

Deleted, formatted, partition gone (logical loss)

A deleted file, emptied Recycle Bin, accidentally formatted drive, “vanished” partition. Here’s the good news: the hardware is fine, only the record-keeping is broken. When you delete a file, the system doesn’t physically overwrite it — it just marks its space as free and the content remains on the disk until something new is written over it. That’s why this is the most common and also the most solvable scenario, one you can often handle yourself (see below). The key is to immediately stop writing to the drive.

Drive clicking, head crash, scratched platters (physical failure)

Clicking, ticking, screeching, the drive won’t spin up. Inside a platter drive, the read/write heads fly just nanometers above the surface; when they start scraping, every additional spin-up risks physically scraping off the layer where the data lives — and then it’s gone for good. This can’t be solved at home: opening a drive outside a cleanroom lets in dust that gets trapped between the platter and the head and finishes the job. Rule #1 applies here: shut it down and don’t gamble.

Fried drive electronics (PCB, power surge)

A power surge, faulty PSU, or lightning can burn out the drive’s controller board (PCB). The platters and data are usually fine; the drive just “shows no signs of life.” The solution is replacing the electronics — but not “buy the same drive from a second-hand shop and swap the boards”: modern drives have calibration data tied to the specific unit (the ROM chip must be transferred). That’s a job for a lab.

SSD is a completely different story (and surprisingly worse)

With SSDs, what holds true for a platter drive doesn’t apply. The main difference is the TRIM function: as soon as you delete a file, the system tells the SSD that the space is free, and recovering deleted data then becomes difficult to impossible. On an internal SSD with active TRIM, a recovery program may only find file names, or nothing at all. Behavior varies with external USB drives, older systems, and certain controllers, but the safe rule remains the same: shut it down, don’t install anything on the affected drive, and don’t write to it. And when an SSD’s controller dies, it’s straight to the lab (reading memory chips directly) — no home software will help there.

Encrypted drive (BitLocker)

This one is simple and merciless: even a perfectly read drive is useless without the encryption key. Data recovery can restore the medium, not crack the encryption. If the drive was encrypted with BitLocker, you’ll need the recovery key — without it, not even a pro can help.

Summarized in a table:

What NOT to do above all (how people destroy their own data)

This is the most practical part. Most of the permanently lost data we see wasn’t lost to the failure — it was lost to the reaction to it.

• Don’t run chkdsk or “repair” tools on a dying drive. Data recovery specialists say it bluntly: on a failing drive, chkdsk overwrites the file system, scrambles the structure, and makes recovery much more complicated — and finishes off the mechanics. We cover this in detail in the bad sectors article; here, the takeaway is enough: until you have the data out, no “repairs.”
• Don’t install a recovery program ON the same drive and don’t write anything to it. Deleted data sits on the drive until it’s overwritten — and installing a program (or anything downloaded) is exactly the kind of write that can overwrite it. Always recover from a different computer and to a different drive.
• Don’t reinstall Windows until the data is out. A reinstall is a massive write across the entire drive; what’s more, newer Windows versions immediately re-encrypt the drive with a different key. Data out first, then the system.
• The freezer is a myth — seriously, don’t do it. The advice to “stick the drive in the freezer for a few hours” is folklore from the 90s, and today’s labs unequivocally warn against it: condensation introduces water into the drive, which on a spinning platter causes a head crash and oxidation. A drive that needed an inexpensive repair thus turns into an expensive head replacement. The freezer makes the problem more expensive, not solved.
• Don’t open the drive at home. “Let me take a peek inside” on the kitchen table = dust on the platters and the data is gone. A cleanroom exists for a reason.
• Don’t keep shooting photos on a card you want to recover deleted photos from. Take it out of the camera. Every new shot can overwrite the deleted one.

Before you try it yourself: why it pays to ask first

The internet (and now AI too) is full of guides saying “download some recovery tool and save it yourself in five minutes.” Let’s be straight about this, because we see it in the service center all the time: this is how a lot of people lose their data completely. The catch is that from the outside, you can’t tell whether the drive is truly healthy or already silently failing — and if it is failing, every DIY attempt only makes the situation worse.

And today, this goes double: modern drives have several layers of protection — spare sectors, error correction, internal health monitoring. As long as they work, the drive appears fine on the outside. Once you lose one of those layers, recovery can suddenly become difficult — or no longer possible at all. And the fact that data was lost is often not a coincidence; there’s usually an incipient fault behind it, one that a “quick fix from the internet” only accelerates.

Safe recovery doesn’t start by installing a tool on the affected drive. First, you address reading on another computer and saving to another medium — and for a risky drive, preferably a bit-level copy.

So from our experience, the safest advice sounds like this:

• If you truly care about the data, don’t gamble with attempts and come in instead. We do an initial HDD assessment for data recovery for free and with no obligation — we’ll tell you straight up whether it’s a five-minute case or a fault where every additional attempt reduces the chances. Before you ruin something at home, this always works out better.
• A drive that clicks, disappears from the system, or doesn’t respond after a fall or spill — don’t try to “revive” it at all. Shut it down (Rule #1) and bring it in as is.
• Don’t install anything on the affected drive or reinstall it. Even a “harmless” attempt can overwrite exactly what you want back.

You might think this caution is overkill for an ordinary deleted file. But damaging a drive is easy — and you often won’t even notice, because from the outside you can’t tell what condition it’s really in underneath. We do an initial HDD diagnostic for data recovery for free, so if you want certainty, the cheapest and safest route is to come in, not experiment at home.

Shut the drive down immediately and don’t try anything if: it clicks, beeps, or screeches · it’s not detected at all · it suffered a fall, spill, or power surge · it’s an SSD with a dead controller · it’s encrypted and you don’t have the recovery key · or the data simply isn’t replaceable and you don’t want to risk even one extra attempt. In these cases, every extra minute reduces the chances — bring the drive to us.

Professional recovery: what it can do and why it costs more

When a drive is physically damaged, the work begins that you can’t do at home. The lab works in a cleanroom (class 100) — a dust-free environment where a drive can be opened without dust destroying the platters. It can handle read/write head replacement from a donor drive, platter transplantation, electronics repair with firmware transfer, or, for flash memory, reading chips directly.

Illustrative photo. Physical recovery is done in a cleanroom — open drive, head replacement, donor drive for spare parts. That’s why it costs orders of magnitude more than software recovery and why we don’t do it “on the spot” on a workbench.

And now, honestly, about the price, so no one is surprised: data recovery isn’t cheap. Software recovery from a functional drive is relatively affordable (for us, typically starting in the low thousands of CZK). Once you’re dealing with bad sectors, a dead SSD, mechanics, donor parts, or RAID/NAS, the price and timeline depend on the specific fault. The initial HDD assessment for data recovery is free; the recovery itself is paid according to the scope, and it only makes sense to quote a price after diagnostics. With a physically damaged platter, no honest professional will guarantee 100% success. Anyone promising “a clicking drive, cheap and fast” either doesn’t know what they’re talking about or is exaggerating.

It’s equally important to know what professional recovery can’t do: bring back blocks that have already been overwritten, bypass BitLocker without the recovery key, or miraculously read a spot where the head physically scraped the magnetic layer off the platter. A serious result is an honest assessment of the chances and a list of recoverable data, not a promise of “100% at any cost.”

Got a NAS or RAID? Don’t try a blind rebuild

When a disk fails in a multi-disk array (NAS, RAID), it’s tempting to immediately start rebuilding the array. Watch out: during a rebuild, the array runs under maximum load precisely when it’s most vulnerable — and a second disk can fail right then. One wrong step overwrites the parity and “one disk failed” turns into “I lost everything.” When a disk (or two) fails, shut the array down and get advice before you start overwriting anything. And don’t forget: RAID is protection against disk failure, not a backup — it won’t help you against deletion or ransomware.

The best recovery is the one you don’t need

This has to be said, even if it sounds like a cliché: even the best data recovery is expensive, uncertain, and comes too late. The only truly calm safety net is a backup following the 3-2-1 rule — and basic backup can be set up in a few minutes. Let me remind you of one number from the bad sectors article: nearly a quarter of drives fail completely without warning. Relying on the idea that “the drive will let me know in time” is a bet that a quarter of people lose.

When it’s about data, reach out sooner

If you’re unsure, or the drive is making noises and the data is valuable, don’t gamble with extra attempts. At our service center in Brno, we’ll first assess the drive and tell you whether it’s a case for DIY, for software recovery, or for data recovery in the lab — including whether it’s even worth it. For urgent cases (clicking drive, ransomware), call the 24/7 line at 775 556 063; if it’s not urgent, write to info@servispc-brno.cz and describe the device, what happened, and how important the data is.

In summary: for a deleted file on a healthy drive, recovery often succeeds — but whether the drive is truly healthy is hard to tell from the outside, and with a clicking drive, every extra attempt is a risk. When the data is valuable, don’t gamble: shut the drive down and, for an HDD, have it assessed for free first. And however it turns out, the same thing always holds true: a backup is always cheaper than recovery.