What backing up your computer actually means
Backing up your computer means making a copy of your files and storing that copy somewhere separate from your machine. If your hard drive fails, gets stolen, or your computer stops working, you still have those files on the backup. You are not moving files — you are duplicating them so they exist in two places.
Most people back up to either an external hard drive (a portable device you plug in), cloud storage (files stored on the internet), or both. The external drive is faster for large amounts of data. Cloud storage works from anywhere and protects against theft or physical damage to your home. Many people use both methods because they protect against different kinds of problems.
Key Takeaways
- Windows computers have a built-in backup tool called File History that automatically copies changed files to an external drive once you plug it in and set it up.
- Mac computers have Time Machine, which works the same way — it backs up automatically to an external drive after you connect it and enable the feature.
- Cloud storage services like OneDrive, Google Drive, or iCloud sync your files to the internet, protecting them if your computer is stolen or damaged.
- The fastest way to start is plugging in an external hard drive and turning on automatic backup, which then runs without you doing anything.
- You should test your backup by trying to restore a file from it before you actually need it, so you know it works when something goes wrong.
Backing up a Windows computer with File History
Windows includes a built-in backup tool called File History that automatically backs up your documents, photos, videos, and other personal files. It does not back up Windows itself or your programs — only your data. This is usually what you need, because you can reinstall Windows and your programs, but your files are irreplaceable.
To set up File History, plug in an external hard drive, then open Settings by pressing the Windows key and typing "settings". Click System, then scroll down and click About. On the right side, click Advanced system settings, then click System Protection. Click Configure, select "Turn on system protection", and click OK. Then go back to Settings, click System, scroll to Backup, and click Backup and recovery options. Under "Back up using File History", click Add a drive and select your external drive. Windows will then back up automatically whenever the drive is plugged in.
File History backs up every hour by default, but you can change this. In the same Backup and recovery window, click More options, then scroll down to "Back up my files" and choose how often you want backups to run. Most people leave it at one hour. You can also choose which folders to back up — by default it backs up your Documents, Pictures, Videos, and Desktop folders.
Backing up a Mac with Time Machine
Time Machine is the Mac equivalent of File History. It automatically backs up everything on your Mac except the operating system itself. Like File History, you can reinstall macOS if something goes wrong, but Time Machine preserves all your files and settings.
Plug in an external hard drive, then click the Apple menu and select System Settings. Click General, then click Time Machine. Click Add Backup Disk and select your external drive. If the drive is new, macOS will ask if you want to erase it — click Erase. Time Machine will then start backing up automatically. The first backup takes several hours depending on how much data you have. After that, it backs up every hour while the drive is plugged in.
You can see what Time Machine is doing by clicking the Time Machine icon in the menu bar at the top right of your screen. If you want to restore a file, click the Time Machine icon, navigate to the date when the file was in the state you want, find the file, and click Restore. Time Machine will copy it back to your computer.
Using cloud storage to back up over the internet
Cloud storage services store your files on the internet instead of on a physical drive. The main advantage is that your files are protected even if your computer is stolen, your house floods, or your external drive fails. The main disadvantage is that cloud storage is slower than an external drive and usually costs money for large amounts of storage.
Windows computers come with OneDrive built in. Click the OneDrive icon in your taskbar (bottom right), then click the three dots and select Settings. Under Account, click Choose folders to sync and select which folders you want backed up to the internet. OneDrive will then sync those folders automatically whenever you are connected to the internet. The free version gives you 5 gigabytes of storage, which is enough for documents and photos but not for video files.
Mac computers come with iCloud built in. Click the Apple menu, select System Settings, click your name at the top, then click iCloud. Turn on iCloud Drive and select which folders you want synced. Like OneDrive, the free version gives you 5 gigabytes. If you need more storage, both services charge a monthly fee — usually around $2 to $10 depending on how much space you need.
You can also use Google Drive on either Windows or Mac. Download Google Drive for desktop from google.com/drive/download, install it, and sign in with your Google account. It works the same way as OneDrive and iCloud — you choose folders to sync and they back up automatically. Google Drive also gives you 15 gigabytes free.
Choosing between external drives and cloud storage
An external hard drive is faster and cheaper for large amounts of data. A 2-terabyte external drive costs around $50 to $100 and can hold years of photos, videos, and documents. The downside is that it only backs up when the drive is plugged in, and if your house burns down or floods, the drive might be damaged too.
Cloud storage is slower but protects against physical disasters. It costs money if you need more than 5 to 15 gigabytes, but it works automatically as long as you are connected to the internet. The downside is that if someone hacks your account, they could delete your files from the cloud too.
The safest approach is using both. Back up to an external drive for speed and large files, and also sync important documents and photos to cloud storage. This way, you are protected against hard drive failure, theft, and physical disasters.
Testing your backup before you need it
A backup that does not work is worse than no backup at all, because you might not realize it is broken until your computer fails and you actually need it. Before you rely on your backup, test it by restoring a file.
For File History on Windows, right-click a file you backed up, select Restore previous versions, choose a date from the list, and click Restore. The file will be copied back to its original location. For Time Machine on Mac, click the Time Machine icon in the menu bar, navigate to an old date, find a file, and click Restore.
For cloud storage, sign into your account from a different computer or phone and download a file. This confirms that your files actually made it to the cloud and that you can get them back if your computer stops working.
What to do if your backup is taking too long
The first backup of a computer with a lot of files can take many hours or even days. This is normal. File History and Time Machine both run in the background, so you can keep using your computer while they back up. Do not unplug the external drive until the backup is finished — you can check by looking at the backup progress in Settings.
If you want to speed things up, close programs you are not using and avoid moving large files around while the backup is running. Backing up over the internet is slower than backing up to an external drive, so if you are using cloud storage and it is taking a very long time, try backing up to an external drive first, then syncing important files to the cloud.
Frequently Asked Questions
Do I need to back up my entire computer or just my files?
You only need to back up your files. Windows and macOS can be reinstalled from scratch if something goes wrong, and your programs can be reinstalled from the internet. Your files are what you cannot replace, so focus on backing up your Documents, Pictures, Videos, and Desktop folders.
What size external drive do I need?
Get a drive that is at least as large as the amount of data you have, plus extra space. If you have 500 gigabytes of files, a 1-terabyte drive gives you room to grow. Most people do not need more than 2 terabytes unless they store a lot of video.
Can I use the same external drive to back up multiple computers?
Yes, but each computer needs its own folder on the drive. File History and Time Machine will create separate backup folders automatically, so you can plug the same drive into different computers and they will each back up to their own space.
What happens if I unplug my external drive while a backup is running?
The backup will stop, but it will not damage your files. The next time you plug the drive in, the backup will resume where it left off. However, you will not have a complete backup until the process finishes, so avoid unplugging the drive while it is working.
Is cloud storage safe from hackers?
Cloud storage companies use encryption and security measures, but no system is completely safe. Use a strong password for your cloud account and enable two-factor authentication if the service offers it. This makes it much harder for someone to access your files even if they get your password.