Before you sell, donate, or recycle an old computer, you need to make sure your personal data is really gone, not just hidden. This guide shows you how to securely wipe a Windows PC or a Mac and dispose of it responsibly. Plan on an hour or two, mostly hands-off while the wipe runs.
Step 1: Back up anything you need first
A wipe is permanent, so rescue your files before you start.
- Copy documents, photos, and downloads to an external drive or the cloud.
- Note any software license keys or app settings you'll want again.
- Double-check the backup actually opened before moving on. Our guide to backing up your files walks through this.
Step 2: Sign out of and deauthorize your accounts
If you skip this, the next owner could be linked to your accounts, and you could be locked out of services that count this device against a device limit.
- Sign out of email, cloud storage, password managers, and browsers.
- Mac: Sign out of iCloud (System Settings > [your name] > Sign Out) and, in the Music or TV app, choose Account > Authorizations > Deauthorize This Computer.
- Windows: Sign out of your Microsoft account and any Microsoft 365 apps.
- Deauthorize streaming or creative apps (like Adobe) that limit how many devices you can use.
Step 3: Erase the drive
Deleting files or doing a "quick format" is not enough. Those just remove the labels while the data stays recoverable. Use the built-in reset tools below, which do a proper job.
Windows
- Go to Settings > System > Recovery.
- Under Reset this PC, click Reset PC.
- Choose Remove everything.
- When asked, choose the option to clean the drive (sometimes labeled "Remove files and clean the drive"). This takes longer but makes data far harder to recover.
- Follow the prompts and let it finish.
Mac
- On recent Macs, go to System Settings > General > Transfer or Reset and choose Erase All Content and Settings. This securely erases your data and resets the Mac, similar to a new iPhone.
- If that option isn't available (older Macs), restart into Recovery (hold the power button on Apple silicon, or Command-R on Intel Macs), open Disk Utility, erase the internal drive, then quit and reinstall macOS.
Step 4: Know when wiping isn't enough
For most people, a proper reset is plenty. But for extremely sensitive data (financial records, medical files, business client data), the safest path for an old drive you're retiring is physical destruction. Drilling through a hard drive or shredding it through a certified service ensures the data can never be recovered.
If the computer used full-disk encryption (BitLocker on Windows, FileVault on Mac), wiping is even more reliable, because the data was already scrambled and the wipe throws away the key.
Step 5: Recycle responsibly
Don't toss electronics in the trash. They contain materials that shouldn't go to a landfill.
- Use a certified e-waste recycler or a manufacturer take-back program.
- Many cities, including those across Los Angeles and Orange County, run e-waste drop-off events.
- If you're donating, the reset in Step 3 leaves a clean machine ready for its next owner.
Tips
- Turn on encryption from day one. Enable BitLocker (Windows) or FileVault (Mac) when you set up any new computer. It protects you if the device is lost or stolen, and it makes future wiping simpler and safer.
- Remove and keep the drive if you're nervous: pull the SSD or hard drive before recycling the rest of the machine.
Troubleshooting
- Reset won't start or errors out: Restart and try again; on Windows you can also reinstall from a recovery USB.
- Not sure the wipe worked: When the computer reboots to a fresh "set up" screen with no accounts or files, the wipe succeeded.
How Gecadi can help
If you're retiring several machines, or you handle sensitive client data and want certified, documented wiping, we can help. Gecadi provides secure desktop support and data handling, on-site across Los Angeles and Orange County and remotely across the U.S., 24/7. For more on protecting information your business is responsible for, read our guide to small-business data privacy.