Factory Reset (Werksreset)

Before returning a company phone or laptop, many people reach for the factory reset. The device then starts up like new, but is the data really securely erased? This entry explains what a factory reset does on PCs, smartphones and printers, where its limits lie and why in companies it does not replace proof of erasure.

How the factory reset works per device

Device	Typical function	What happens
Windows PC	"Reset this PC" with "Remove everything"	Windows is reinstalled. The data is only overwritten with the additional option to clean the drive, which takes significantly longer.
iPhone, iPad, current Macs	"Erase All Content and Settings"	The keys of the encrypted storage are deleted. The data is then no longer readable.
Android smartphones	"Factory data reset"	With active device encryption, the keys are removed; implementation varies by manufacturer.
Printers and multifunction devices	Manufacturer-specific erase or initialization function	Depending on the model, the internal hard drive or memory is overwritten, or only settings are reset.

With encrypted devices, the reset essentially acts like a Crypto Erase: it is not the data but the keys that are destroyed.

Limits and risks

• No proof: The reset produces no report with serial number, method and result. For the accountability obligation under the GDPR, the evidence is therefore missing.
• Depends on encryption: Without encryption, data may remain recoverable. A simple reinstallation is more like a Quick format.
• Manufacturer quality: Whether all storage areas are covered can hardly be checked from outside.
• Locks remain: If the device is still linked to an account, after the reset the Activation Lock on Apple or the Factory Reset Protection on Android takes effect. The device can then neither be used nor sold.
• Device management: If a device is registered in an MDM it can automatically sign in again after the reset.

Factory reset in IT retirement

For individual private devices, a factory reset can be enough. Companies, by contrast, need a procedure that documents for every data carrier how and with what result it was erased. Before handing over, you should additionally sign out accounts, remove locks and release devices from device management. Why the reset is not enough for company phones is explained in our guide retiring company phones. How to release tablets from MDM locks is described in Selling tablets: company iPads without MDM lock. If a device is already on its way or lost, only a Remote wipe.

Factory reset and Second IT

Second IT erases laptops, PCs, smartphones and tablets software-based with Blancco, and on hard drives also hidden areas such as HPA and DCO. A digitally signed erasure certificate with serial number is issued for every device. Data carriers that cannot be erased are destroyed in-house according to DIN 66399 (up to security level H-5 and E-5). More on certified data deletion.

Frequently asked questions about the factory reset

Does a factory reset erase all data?

That depends on the device. On current, encrypted smartphones and Macs, the keys are deleted, which makes the data unreadable. On unencrypted hard drives, a simple reset often only reinstalls the system. It does not provide verifiable evidence in any case.

What do I need to consider before a factory reset?

Back up the data you need, sign out user accounts such as Apple ID or Google account and release the device in device management. Otherwise locks remain active, and the device is blocked for a new user.

Is a factory reset enough for printers?

Often not. Many multifunction devices store print and scan jobs on an internal hard drive. Whether the reset function actually overwrites it depends on the model. It is safer to erase or destroy the data carrier with certification.

How do I reset a Windows PC to factory settings?

Use "Reset this PC" and select "Remove everything". Windows is then reinstalled. The data is only overwritten if you additionally select the option to clean the drive. That takes significantly longer but does not replace proof of erasure.

Why is a device still locked after the factory reset?

If the device is still linked to an account, after the reset Activation Lock on Apple or Factory Reset Protection on Android takes effect. The device can also sign in automatically again in an MDM. Therefore sign out accounts beforehand and release the device.