Hard drives fail. Laptops get stolen. Ransomware happens. And every single day, someone loses years of photos and documents because ‘I kept meaning to back up.’ If you’re reading this, consider it your sign: backing up your computer to an external hard drive takes about 30 minutes to set up, and then it runs itself.
You don’t need fancy software or technical skills. Both Windows and Mac have excellent built-in backup tools that most people have never opened. Here’s how to use them, what drive to buy, and the mistakes that make backups useless when you actually need them.
What Drive to Buy
Get an external hard drive (HDD) with at least twice the capacity of your computer’s internal storage. If your laptop has 512GB, buy a 1TB or 2TB external drive — backups accumulate over time, and running out of space mid-backup is how people abandon the habit. A 2TB portable drive costs $60 to $80 in 2026.
Portable vs desktop: portable drives (2.5-inch, USB-powered) are small, silent, and need no power brick — ideal for laptops. Desktop drives (3.5-inch, with power adapter) offer more terabytes per dollar for desktop PCs that never move.
SSD vs HDD for backup: HDDs win on price per terabyte for backups. SSDs are faster and more drop-resistant but cost 2-3x more. For a backup drive that sits on a shelf, HDD is the smart money. Our guide to the best external hard drive for family photos goes deeper on specific models.
Backing Up Windows With File History
1. Plug in your external drive. Windows should recognize it immediately.
2. Go to Settings > System > Storage > Advanced storage settings > Backup options (or search ‘File History’ in the Start menu).
3. Click ‘Add a drive’ and select your external drive.
4. Toggle on ‘Automatically back up my files.’ Click ‘More options’ to choose how often (hourly is the default; every few hours is fine) and how long to keep backups.
File History backs up your personal folders — Documents, Pictures, Desktop, Downloads — continuously in the background. It’s simple and reliable for what most people need.
For a full system image (everything, including Windows itself and your programs), search for ‘Backup and Restore (Windows 7)’ in the Start menu — yes, it still exists in Windows 11 — and choose ‘Create a system image.’ Do this once after major setups; File History handles the day-to-day.
Backing Up a Mac With Time Machine
1. Plug in your external drive. Time Machine may ask if you want to use it for backup — say yes.
2. If it doesn’t prompt you, open System Settings > General > Time Machine, click ‘Add Backup Disk,’ and select your drive.
3. Time Machine will ask to erase the drive (it needs its own format). Let it — use a dedicated backup drive, not one with other files on it.
4. Toggle Time Machine on. The first backup takes a while (possibly hours); afterward, hourly backups run silently whenever the drive is connected.
Time Machine is genuinely one of the best backup tools ever made — full system, versioned hourly, and restoring is as easy as browsing a timeline. The catch: the drive needs to be connected regularly. A backup drive in a drawer doesn’t back up.
Backup Mistakes That Defeat the Purpose
Keeping the backup drive plugged in 24/7. Ransomware encrypts attached drives too. Plug in, back up, unplug — or at least disconnect when you’re not actively backing up.
Having only one backup. The 3-2-1 rule: 3 copies of important data, on 2 different media types, with 1 offsite. Your external drive is copy #2. Add cloud backup (Backblaze, iCloud, Google One) for the offsite copy — it’s $6-$10/month for peace of mind.
Never testing the restore. Once a year, try restoring a single file from your backup. A backup you’ve never tested is a backup you hope works.
Encrypting without recording the password. If you enable BitLocker/FileVault on the backup drive, store the recovery key somewhere safe (printed, in a password manager). An encrypted backup with a lost key is just a paperweight.
How Often Should Backups Run?
The answer depends on how much you can afford to lose: hourly (Time Machine/File History default) for active work machines — a crashed laptop costs you an hour, not a week. Daily is the minimum I’d accept for any computer holding important files. Weekly is the absolute floor, and only if the computer is lightly used.
The real question isn’t frequency — it’s automation. Manual backups fail because humans forget. Whatever schedule you choose, make it automatic: Time Machine hourly when the drive’s connected, File History on its schedule, Backblaze continuous. Set it once, verify monthly that it’s actually running (open the app, check the last backup date — 30 seconds). A backup system you never check is a hope, not a system.
Special cases: before any OS upgrade, before traveling with the laptop, and before letting anyone ‘borrow’ your computer — run a manual backup. These are the highest-risk moments in a computer’s life.
What About Ransomware Specifically?
Ransomware encrypts everything it can reach — including connected backup drives. Defense in depth: keep the backup drive DISCONNECTED except during backups (ransomware can’t encrypt what it can’t see), maintain the offsite cloud copy (Backblaze keeps 30-day version history — you can restore pre-encryption versions), and enable controlled folder access (Windows Security > Ransomware protection) which blocks unauthorized apps from modifying your documents.
If infected: disconnect from the internet immediately, do NOT pay (funds criminals, decryption often fails anyway), restore from the disconnected backup or cloud version history, and report to CISA/FBI IC3. Prevention (backups + skepticism about attachments) beats every cure. Our antivirus guide and phishing guide cover the other layers.
A tested, disconnected backup turns ransomware from a catastrophe into an inconvenience. That’s the whole game.
The Bottom Line
Buy a 2TB portable drive, plug it in, turn on File History or Time Machine, and let it run. Total active effort: 30 minutes. Then add a cloud backup for the offsite copy when you’re ready. Future you — the one whose laptop dies the week before a big deadline — will be enormously grateful that present you spent half an hour on this.