How to Securely Wipe an Old PC or Mac Before Selling It

Selling, donating or recycling an old computer? A simple 'delete files' or even a quick factory reset can leave your tax returns, saved passwords and logged-in accounts recoverable with free tools. Here's how to do it properly.

Before you wipe: 4 essential steps

1. Back up everything you want to keep to an external drive or the cloud.
2. Sign out of and de-authorise accounts: iCloud, iTunes, Adobe, Microsoft 365, Dropbox.
3. Turn off Find My Mac (macOS) or your Microsoft account device link (Windows) so the new owner isn't locked out.
4. Deactivate any software licences tied to the hardware (Office, Photoshop, antivirus).

Windows: the proper wipe

1. Settings → System → Recovery → Reset this PC → Remove everything.
2. Choose 'Local reinstall' or 'Cloud download'.
3. Critical: click 'Change settings' and turn ON 'Clean data' — this overwrites the drive so files can't be recovered. (This step is the one most people miss.)
4. Let it run — it can take 1–3 hours with clean-data enabled. That's normal.

Mac: the proper wipe

1. Apple Silicon or T2 Macs: simply use System Settings → General → Transfer or Reset → Erase All Content and Settings. Because the SSD is hardware-encrypted, this instantly and irrecoverably wipes it.
2. Older Intel Macs without T2: boot to Recovery (Cmd+R), open Disk Utility, erase the drive as APFS, then reinstall macOS.

If the PC won't boot or you're recycling it

If the machine is dead and headed for recycling, the only guaranteed method is to physically remove the drive and either keep it, or (for HDDs) destroy the platters. For SSDs, a secure-erase utility from the manufacturer is best. We handle certified data destruction for businesses on request.