How to Wipe Data Before Selling a Computer, Laptop or Phone: Why Deleting Files and Even Formatting Don't Truly Erase Them, and What to Do So the New Owner Doesn't Get Your Photos, Passwords and Documents

An old laptop is sold on an online marketplace, a phone is traded in when buying a new one, a departed employee's computer is passed on to someone else or donated to charity. Beforehand, people usually delete "their" folders, empty the recycle bin or, at best, format the drive. But data recovery specialists know well that photos, documents, messages, saved passwords and even account access can often be recovered from such devices. Studies of drives bought second-hand regularly show that a significant share still hold personal and corporate data from previous owners. Let's look at how to erase it properly.

Why deleting and formatting aren't enough

When you delete a file and empty the recycle bin, the system merely marks the space it occupied as free. The data itself stays on the drive until something new overwrites it. A quick format creates a new, empty index but leaves the drive's contents untouched. That's exactly why recovery after accidental deletion is often possible — and for the same reason, any buyer with a free program can find your files on a drive you've sold.

Hard drives

For an ordinary hard drive, the reliable method is a full overwrite of the entire drive — for example, a full format in modern versions of Windows, or a dedicated program that writes zeros across the whole surface. A single pass is enough for modern drives. If the drive is faulty and can't be overwritten, and the data on it is confidential, the only reliable option is physical destruction.

SSDs are a special case

Solid-state drives spread writes across cells and have hidden spare areas, so an ordinary overwrite may miss some of the data. For an SSD, the right method is a secure erase command carried out by the drive's own controller, or a cryptographic erase if the drive was encrypted: destroying the encryption key makes all the data unreadable instantly. These functions are available through manufacturers' utilities and some BIOS settings.

Encryption — the best preparation in advance

If a computer's drive is encrypted from the start, for example with Windows' or macOS's built-in tools, selling it becomes much safer: once the key is removed and the system reinstalled, the old data can't be read without the password. Modern phones are encrypted by default, so a factory reset works more reliably on them than on old computers.

Phones and tablets

• Make a backup and check that it restores on the new device.
• Sign out of your Apple ID or Google account and turn off the find-my-device feature — otherwise the new owner won't be able to use the phone and your account stays linked to it.
• Unlink the phone from messengers, banking apps and authenticators, and move them to the new device.
• Perform a factory reset.
• Remove the SIM card and memory card.

Computers and laptops

• Save all the data you need, including email, browser passwords and software licences.
• Deactivate software licences tied to the device.
• Sign out of cloud accounts and unlink the device from your Microsoft or Apple account.
• Erase the drive using the right method for its type, and install a clean system if the buyer expects one.

What people forget

External drives and USB sticks handed over "along with the computer". Memory cards in old cameras and dashcams. Office MFPs and printers that keep scanned documents and an address book in internal memory. Network storage devices and routers holding saved passwords and settings. Games consoles with linked accounts and payment cards.

What our technician does

1. Helps save and move all the data, accounts and licences you need to the new device.
2. Unlinks the old device from accounts and device-finding services.
3. Erases the drive using the method suited to an HDD or SSD and, if needed, verifies the result.
4. Installs a clean system for sale or prepares the device for recycling.
5. If necessary, physically destroys faulty drives holding confidential data.

A real example

The owner of a small firm in Saburtalo decided to sell five old office laptops. The staff had "cleaned" them themselves — deleted folders and emptied the recycle bin. Before selling, he nevertheless asked us to check one laptop: within an hour we recovered hundreds of documents containing client data, online banking passwords saved in the browser and work correspondence. We then moved what was needed, unlinked the laptops from accounts, performed a secure erase of the SSDs with the manufacturer's tools and installed a clean copy of Windows. The laptops went to their buyers without a single company file.

If a device is faulty and won't switch on, that doesn't mean its data is out of strangers' reach. A laptop with a cracked screen or a dead board can be sent for repair or sold for parts, and the buyer can easily remove the drive and read it on another computer. So before selling broken equipment, remove the drive and keep it, erase it on another computer or destroy it. In phones the memory is soldered to the board and encrypted, but here too it's best to sign out of accounts through the services' websites and unlink the device remotely beforehand.

Call a technician

If you're about to sell or hand over a computer, laptop or phone, we'll help you prepare it safely in any district of Tbilisi. Learn more on our computer setup, computer diagnostics and data recovery pages.