How to erase data before selling or scrapping a computer
When a machine changes hands, the data goes with it unless you actively do something. A quick format only removes the index — the files are still there and can be recovered with free tools.
For a personal machine
Sign out of everything first: Microsoft account, Google, iCloud and any disk encryption. Then run Windows' own reset with the option that removes everything and cleans the drive. That overwrites, rather than simply deleting the references.
If the machine has been running with BitLocker or FileVault enabled, it is simpler: delete the key and the data is effectively unrecoverable.
SSDs and hard disks are not the same
On an old-fashioned platter hard disk, overwriting works. On an SSD the controller moves data around, so an overwrite does not necessarily reach every cell. For SSDs you use the manufacturer's Secure Erase, found in their own tool, or you destroy the drive physically.
For a company that is not enough
If the machine has held personal data, you have to be able to document that it is gone — not merely know it. Require an erasure report with a serial number for each individual device from whoever handles the equipment. That is the document you need to be able to produce if anyone asks.
Remember BIOS passwords and device locks too. A machine still tied to your management system is unusable for the next owner.
If you would rather have it done
If we buy your equipment, erasing the data is part of the deal and the documentation comes with it. You are also welcome to just ask for the advice — that costs nothing.
Write to usMore guides
- Repair or replace? How to work it outThe calculation that decides whether a slow or broken machine gets repaired or replaced.
- How to upgrade the memory in a laptopThe cheapest upgrade there is — if the machine can take it at all.
- Ten things to check on a used laptop before you buyA ten-minute check that reveals what the seller left out of the listing.
Let us find the right solution for you
Tell us about your situation and we will come back with a concrete proposal — no obligation and no sales pitch.