What backing up your PC actually means

Backing up your PC means making a copy of your files and storing that copy somewhere separate from your computer. If your hard drive fails, gets infected with malware, or you accidentally delete something important, you still have the original copy on the backup. The backup lives on an external drive, a cloud service, or both.

Most people think of backups as something you do once and forget about. That does not work. A backup is only useful if it is recent — ideally within the last few days. If your drive fails on a Wednesday and your last backup was three weeks old, you have lost three weeks of work, photos, and documents.

Key Takeaways

  • A backup is a copy of your files stored somewhere other than your computer, and it only protects you if it is recent enough to matter.
  • Windows PCs have a built-in backup tool called File History that copies changed files automatically if you plug in an external drive regularly.
  • External hard drives are cheap and fast for backups, but they only protect you if the drive is plugged in when the backup runs.
  • Cloud backup services like OneDrive, Google Drive, or Backblaze run automatically in the background and protect you even if your physical location has a fire or theft.
  • The safest approach uses both: an external drive for speed and a cloud service for protection against physical disaster.

Using Windows File History for automatic backups

Windows 10 and Windows 11 both include a tool called File History that automatically backs up your Documents, Pictures, Music, Videos, and Desktop folders. It does not back up program files or system settings — only your personal files. To turn it on, plug in an external hard drive, then open Settings, go to System, then About, scroll down and click Advanced system settings, then click System Protection, then click Configure, select "Restore system settings and previous versions of files", and click OK.

Once File History is on, Windows backs up changed files every hour. If you unplug the external drive, backups stop until you plug it back in. This means File History only works if you keep the drive connected most of the time, or if you plug it in regularly — at least once a week. If you forget to plug it in for a month and your drive fails on day 29, your backup is a month old.

File History keeps multiple versions of each file, so you can restore a document from last week, last month, or last year if you need to. To restore files, open File History, click "Restore personal files", navigate to the folder you want, select the files, and click the green restore button.

External hard drives: speed and simplicity

An external hard drive is a storage device you plug into your PC with a USB cable. A 2TB external drive (enough for most people's files) costs between $50 and $100 and holds roughly 2,000 gigabytes of data. It is much faster than cloud backup — a full backup of 500GB takes about an hour on an external drive but can take days on a cloud service if your internet is slow.

The trade-off is physical: an external drive only protects you from drive failure, not from theft, fire, or water damage. If your house burns down, the external drive burns with it. If a thief takes your computer, they can take the external drive too if it is sitting next to your desk. External drives also fail — they have moving parts and typically last five to seven years before the motor wears out.

Buy a drive from a major manufacturer like Western Digital, Seagate, or LaCie. Avoid very cheap drives from unknown brands; the money you save upfront costs you when the drive fails after a year. Keep the drive plugged in or plug it in at least weekly so File History can run.

Cloud backup services: protection against physical disaster

Cloud backup means your files are copied to a company's servers on the internet. Services like OneDrive (included free with Windows), Google Drive, iCloud Drive, or Backblaze run in the background and upload changed files automatically. You do not have to plug anything in or remember to run a backup.

The main advantage is that your files are safe even if your house burns down, floods, or gets robbed. The main disadvantages are speed and cost. Uploading 500GB to the cloud can take weeks if your internet is slower than 10 Mbps. OneDrive gives you 5GB free, which fills up quickly. Google Drive gives 15GB free. Backblaze costs about $7 per month for unlimited backup. iCloud Drive costs $0.99 to $9.99 per month depending on how much space you need.

If you have a slow internet connection, cloud backup is frustrating — it will upload files in the background for months. If you have fast internet (50 Mbps or faster), cloud backup is painless and you will forget it is running.

Combining external drives and cloud backup

The most reliable approach uses both an external drive and a cloud service. The external drive gives you fast access to recent backups if you need to restore a file quickly. The cloud service protects you if the external drive fails or if something happens to your physical location.

Set up File History to back up to an external drive, and separately set up a cloud service to back up your Documents, Pictures, and other important folders. You do not need to back up the same files twice — back up your most important files to the cloud and everything to the external drive. If your internet is slow, back up only your Documents and Photos to the cloud and use the external drive for everything else.

This approach costs money: an external drive ($50–$100) plus a cloud service ($7–$10 per month). For most people, that is worth it. If you have only a few gigabytes of important files and fast internet, a cloud service alone is enough.

What not to back up and what to do before you start

Do not back up your Program Files folder or Windows system files. These are huge, they change constantly, and you do not need them — you can reinstall Windows and your programs from scratch if your drive fails. Back up only your personal files: Documents, Pictures, Videos, Music, Desktop, and any other folders where you store things you created.

Before you set up a backup, delete files you do not need. If your Downloads folder has 50GB of old installers and videos, you are wasting backup space and time. Go through Documents, Pictures, and Desktop and move anything you do not need to the Recycle Bin. This makes backups faster and cheaper.

If you are backing up to the cloud, check your internet speed first. Open speedtest.net in your browser and run a test. If your upload speed is slower than 5 Mbps, cloud backup will be slow. If it is faster than 20 Mbps, cloud backup will be fast enough that you will not notice it running.

Restoring files when something goes wrong

If you delete a file by accident, you can restore it from your backup within minutes. Open File History, click "Restore personal files", navigate to the folder where the file was, find it in the list, and click the green restore button. The file goes back to its original location.

If your entire hard drive fails and you need to restore everything, you will need to reinstall Windows first, then restore your files from the backup. This takes several hours. If you are using an external drive, plug it in after Windows is installed, open File History, and restore all your files. If you are using cloud backup, sign in to your cloud account and read your files.

If you are not comfortable doing this yourself, a computer repair shop can restore your files for you. This costs $100–$300 in labor, which is why having a backup is cheaper than paying someone to recover your files.

Frequently Asked Questions

How often should I back up my PC?

If you use File History with an external drive plugged in, it backs up automatically every hour. If you plug in the drive weekly, you lose at most one week of work. If you use cloud backup, it runs continuously in the background. For most people, hourly or continuous backup is more than enough.

Can I use the same external drive to back up two computers?

Yes, but each computer needs its own folder on the drive. File History creates a folder with your computer's name automatically. If you have a 2TB drive and two computers, each one can back up 1TB. Make sure the drive is plugged in when both computers need to back up, or set them to back up on different days.

What if I run out of space on my external drive?

File History will stop backing up and warn you. Delete old backups you no longer need, or buy a larger drive. You can also tell File History to keep only backups from the last month instead of keeping everything forever — open File History settings and change "Keep my backups" to a shorter time period.

Is cloud backup safe from hackers?

Major cloud services like OneDrive, Google Drive, and Backblaze encrypt your files so that hackers cannot read them even if they break into the company's servers. Your files are safer in the cloud than on an external drive sitting next to your desk. The real risk is someone guessing your password — use a strong password and turn on two-factor authentication if the service offers it.

Do I need to back up my entire PC or just my files?

Back up only your files. Your programs and Windows can be reinstalled from scratch if your drive fails. Backing up everything takes much longer and uses much more space. The only exception is if you have heavily customized Windows settings you want to keep — in that case, use Windows System Image instead of File History, but this is rare and complicated.