Mark it once you can do it without this page open.

How to do it

  1. Decide what matters: documents, photos, tax records and anything you made yourself.
  2. Plug in an external drive at least as large as the computer's drive.
  3. Turn on the operating system's built-in backup tool and point it at the drive.
  4. Leave the drive connected, or plug it in every week, so backups keep running.
  5. Set up a cloud backup or a synced folder for your most important files as the off-site copy.
  6. Restore one file from each backup to prove it works.
  7. Unplug the external drive between backups if you can, so ransomware cannot reach it.

Common mistakes

  • Treating one external drive as a full backup plan.
  • Never testing a restore until the day it is needed.
  • Keeping the backup drive next to the laptop in the same bag.

Quick self-check

Three questions. Your last score is kept in this browser.

1. What does the 3-2-1 rule ask for?
2. How do you know your backup works?
3. Why unplug the backup drive between runs?

Teach this to someone

A one-page sheet for showing a friend, a roommate or a kid: what to say, what to show, and one question to check it landed.

Words on this page

Sources

  • National cybersecurity agency guidance for home users, 2026. Checked September 28, 2026.

Last reviewed . First published .