How to Back Up a Computer to an External Hard Drive

Ryan Dube is a freelance contributor to Lifewire and former Managing Editor of MakeUseOf, senior IT Analyst, and an automation engineer.

Updated on April 1, 2022 Reviewed by

Ryan Perian is a certified IT specialist who holds numerous IT certifications and has 12+ years' experience working in the IT industry support and management positions.

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What to Know

This article explains how to perform a partial or complete backup of your Windows-based PC. The instructions apply to Windows 11 and 10.

How to Make a Partial Backup of Your Computer

While a partial backup of your Windows computer won't protect your operating system settings, it will save all of your important files should you ever need to reinstall Windows.

If you only care about keeping specific files and folders on your computer backed up, you can automatically save all of these to an external hard drive at a regular time interval of your choosing.

Backup settings highlighted from the Windows Start menu

  1. Connect the external drive to your computer, then select the Start menu. In Windows 11, type file history and select File History. In Windows 10, type backup and select Backup settings.

Add a drive highlighted from Windows Backup settings

Select Add a drive to choose the external hard drive you want to use for your file history backups.

Selecting a drive for backup from Windows Backup settings

Doing this opens a Select a drive popup listing all external drives connected to your computer. Select the external drive where you want to back up your important files and folders.

Automatically back up my files toggled on in Windows Backup settings

You will now see Automatically back up my files enabled. It will use a default list of files and folders most users want to keep backed up. To add more files and folders, select More options under the toggle.

The Add a <a href=folder option highlighted from Windows Backup options" width="1920" height="1080" />

Review the folders under Back up these folders. If any are missing from the list, select Add a folder and then browse and choose the additional folders you want to include.

If there are any folders listed that you don't want to include, select it and then select Remove to remove that folder from the list.

How to Make a System Backup of Your Computer

Making a full system backup requires much more space than a partial backup which only includes files and folders. The size requirement depends on your system files, so make sure to clear out the cache and log files to reduce this space requirement. Expect to use over 200 GB for this backup, so you'll need an external hard drive with free space of 250 GB or more.

If you want to make a complete backup of your entire Windows 10 system, this is called a "system image." You can save this system image to an external hard drive for safekeeping off of your computer's internal drive. If you ever need to recover your computer, use this system image to recover your operating system and all settings.

Control Panel app highlighted from Windows Start menu

  1. In the search bar, type control panel and select the Control Panel app.

Backup and Restore highlighted from Windows Control Panel

Select Backup and Restore (Windows 7).

Create a system image option highlighted from Windows Control Panel options

From the left pane, select Create a system image.

Drop-down menu for selecting a hard drive for creating a system image on Windows

In the Create a system image pop-up window, select your attached external hard drive in the On a hard disk drop-down list.

Starting a system image backup on Windows

In the next window, you'll see a list of system partitions that will be backed up as part of the system backup on the external hard drive. Select Start backup to begin the backup process.

Types of Computer Backups

Depending on your needs, there are two types of backups you can perform.

How can I use an external hard drive for backup and storage?

If you have enough space on your external drive, it's possible to use the same device for full computer backups and storing specific files. Otherwise, you may want to consider separate hard drives: one drive for moving files to save space on your computer and the other for backups. On Macs using Time Machine, you'll need to create a new APFS volume on the external hard drive to use part of it for backups and another portion for other file storage.

How do I back up my Mac to an external hard drive?

Use Time Machine to back up your Mac to an external drive. Connect the drive and set it as your preferred backup drive from System Preferences > Time Machine > Select Backup Disk. From there, you can choose manual or automated backups that start at a specific interval when you connect the external drive to your Mac. To back up essential files, manually move them to your external drive or use iCloud.