How to install Windows 10 on external hard drive for free?

Installing Windows 10 on an external hard drive can be a great way to create a portable Windows installation that you can take with you anywhere. It allows you to boot into Windows on any computer by simply plugging in your external hard drive. And the best part is, you can do this without having to pay for an additional Windows license.

Benefits of Installing Windows 10 on an External Hard Drive

Here are some of the benefits of installing Windows 10 on an external hard drive:

  • Portability – You can carry your Windows installation with you and use it on any computer.
  • Isolation – External drive installations don’t modify the host computer’s hard drive or Windows installation.
  • Convenience – Easily choose between operating systems by selecting the boot drive.
  • Cost savings – No need to purchase an additional Windows license.
  • Troubleshooting – Diagnose and repair computer issues by booting from external media.
  • Backup – Provides a portable backup Windows installation in case of problems.
  • Upgradability – Can easily upgrade to newer versions of Windows by doing fresh installs on the external drive.

Requirements for Installing Windows 10 on an External Hard Drive

Before starting the installation process, you’ll need the following:

  • An external hard drive or USB flash drive with at least 16GB of storage.
  • A Windows 10 installation medium – Either DVD or bootable USB.
  • The Windows 10 product key for the version you’re installing.
  • Bootable media creation tool – Such as Rufus.
  • Administrator access to the computer – You’ll need this to change the BIOS settings.

Make sure to back up any important data on the external drive before using it for this process. The drive will be formatted so everything will be deleted.

Step 1: Create Bootable Windows 10 Installation Media

To start, you’ll need to create bootable media that can be used to install Windows 10. This is what will enable you to go through the Windows setup process from the external drive. There are a couple options for creating Windows 10 media:

Option 1: Use Media Creation Tool

Microsoft provides the Windows 10 Media Creation Tool for free. This will download the necessary files directly from Microsoft and create a bootable ISO file for you:

  1. Download the Media Creation Tool from Microsoft at
  2. Run the tool once it finishes downloading. Select “Create installation media for another PC” and click Next.
  3. Choose your language, edition, and architecture (64-bit or 32-bit).
  4. Select “USB flash drive” for the media you want to use.
  5. Plug your flash drive or external hard drive into the computer. The tool will format and create the bootable media for you.

Once finished, you will have Windows 10 installation media on your external drive that you can use for the rest of this process.

Option 2: Use ISO File and Rufus

You can also download the Windows 10 ISO file separately and then use a tool like Rufus to create bootable installation media. Here is the general process:

  1. Download the version of Windows 10 you want as an ISO file from Microsoft.
  2. Download and install the tool Rufus from
  3. Launch Rufus – Select your external drive as the target device.
  4. Select “Create bootable disk using”, then select your downloaded ISO file.
  5. Ensure the file system selected is NTFS and click Start.

Rufus will format the drive and create a bootable version of your Windows 10 ISO. Once it finishes, you will have the installation media ready to go.

Step 2: Plug In the External Hard Drive and Change Boot Order

Now it’s time to start the actual Windows installation process:

  1. Connect your external hard drive with the Windows 10 installation media to the computer.
  2. Restart the computer and press the appropriate key to access the BIOS/UEFI settings when prompted. This is usually the F2, F8, F10 or F12 key.
  3. Navigate to the Boot menu in the BIOS settings.
  4. Change the boot order so that your external hard drive with the Windows 10 media is listed first.
  5. Save the changes and exit the BIOS.

The computer will now boot from your external Windows 10 media instead of the normal internal hard drive.

Step 3: Follow the Installation Process and Format Drive

With the computer booted to your external Windows 10 media, you can proceed with the installation:

  1. The Windows Setup wizard will launch – Follow the prompts to install Windows 10.
  2. When prompted, select “Custom: Install Windows only” for the type of installation.
  3. A screen will show you the current drives and partitions on your computer. Select the external hard drive you want to install Windows on.
  4. Click the “Drive options (advanced)” link at the bottom.
  5. Ensure the external hard drive is selected. Click “Format” to delete any existing partitions and format the drive.
  6. Click Apply, then click Next. Setup will now install Windows 10 to your external hard drive.
  7. Continue following any additional prompts to finish the installation process.

The Windows Setup wizard will take care of creating the necessary partitions on the external drive and installing Windows to it. Once completed, you will be able to boot to Windows 10 directly from the external hard drive.

Step 4: Change Boot Order Back to Original Drive

After you have completed the Windows 10 installation on the external drive, you’ll want to switch the boot order back:

  1. Access the BIOS settings again using the method from Step 2.
  2. Navigate back to the Boot menu.
  3. Restore the boot order to list your normal internal hard drive first.
  4. Save changes and exit.

This will set your original system drive as the primary boot drive again. Your external drive will now be available as a secondary boot option that you can select from the boot menu.

Step 5: Test External Hard Drive Boot

Before you start using your new Windows 10 external installation, it’s a good idea to test it and ensure everything works properly:

  1. Restart your computer.
  2. Access the boot menu again using your BIOS/UEFI key.
  3. Select your external hard drive from the boot menu.
  4. Windows 10 should launch from the external drive.
  5. Verify that it functions correctly and you can access the internet and other resources.

Troubleshoot and reattempt the installation if you have any issues getting the external drive to boot. It’s best to identify and address any problems now before you start using it regularly.

Step 6: Install Drivers and Applications

Once you have tested Windows 10 on your external hard drive and verified that it works, you can start installing any other applications and drivers you need:

  • Install drivers required for your hardware like video cards, networking, etc.
  • Download Windows updates to get the latest patches and security fixes.
  • Set up anti-virus, VPNs, remote access software as needed.
  • Customize Windows settings to your preferences.
  • Install productivity software and tools you regularly use.

Completing any required configuration now means your portable Windows 10 installation will be ready to use whenever you boot from the external drive.

Step 7: Create a Recovery Image (Optional)

Once your external hard drive Windows 10 installation is set up to your specifications, it’s a good idea to create a system image as a backup. This image can be used to restore your installation to a previous state if anything goes wrong.

Here are a couple options for creating a recovery image:

Use the Windows 10 Backup Tool

  1. Boot from the external hard drive into Windows 10.
  2. Type “control panel” into the Start menu and hit Enter.
  3. Select “Save backup copies of your files with File History” under System and Security.
  4. Click “System Image Backup” on the left pane.
  5. Click Create a system image and select the desired external drive as the backup destination.
  6. Windows will create a system image of your installation to the designated location.

Use a Backup Tool Like Macrium Reflect

  1. Download and install the free version of Macrium Reflect.
  2. Run Macrium Reflect and select “Create an image of the partitions required to backup and restore Windows”.
  3. Select your external drive’s partitions C and D. Choose your backup destination.
  4. Click Start and wait for the imaging process to complete.

You now have a system image backup that can be used to restore your portable Windows 10 installation if needed.

Tips for Using Windows 10 on an External Hard Drive

Here are some helpful tips for getting the most out of using and carrying Windows 10 on an external drive:

  • Use a high-quality fast hard drive like a solid state drive or large flash drive for best performance.
  • Connect the external drive directly to a USB 3.0 port if possible for maximum speed.
  • Be careful not to shock or disconnect the external drive while Windows is running to prevent corruption.
  • Disable auto-updates in Windows to prevent unexpected reboots or installation of incompatible drivers.
  • Manually trigger updates when you know you’ll be on fast, stable internet connections.
  • Carry any drivers or applications you need on a second external drive so you can access them if needed.
  • Never connect your Windows 10 external drive to a public computer without protection.
  • Consider using encryption technologies like BitLocker to secure your installation.

Potential Issues and How to Troubleshoot

While installing Windows 10 on an external hard drive is usually a smooth process, you may encounter certain issues. Here are some potential problems and how to troubleshoot them if they occur:

Booting Issues

If you have issues getting the computer to boot from your external drive, try the following:

  • Ensure the drive is listed first in your computer’s boot order in the BIOS.
  • Try a different USB port – Some may not support booting.
  • Check that your drive is formatted with either NTFS or FAT32 file systems.
  • Defragment the drive if you notice slow load times when booting.

Missing Drivers

Windows might not include all the drivers needed for the computer hardware you are using:

  • Identify any missing device drivers in Windows Device Manager.
  • Download the latest driver for that hardware from manufacturer website.
  • Copy the driver files to the external drive and install them in Windows.

Hardware Compatibility

You may experience blue screens, crashes or hardware that doesn’t work under Windows 10:

  • Check if manufacturer has Windows 10 compatible drivers and install them.
  • Try updating BIOS/firmware for motherboard.
  • Some older hardware may not work – Consider upgrading components.

Windows Activation Issues

If Windows 10 fails to activate on your external installation:

  • Ensure you have a valid Windows 10 product key for version you installed.
  • Check that you are connected to the internet.
  • Confirm the date/time is set correctly on your computer.
  • Go through activation process again or contact Microsoft support.

Frequently Asked Questions

Here are answers to some common questions about installing Windows 10 on an external hard drive:

Is Windows 10 portable if I install on external drive?

Yes, installing Windows on an external drive makes it completely portable. You can connect the drive to and boot from any modern PC that supports booting from USB.

Can I install programs and games onto the external drive?

Absolutely! Install and run all your programs and files from the external drive. Just be sure to have enough storage space available.

Does Windows run slower on an external drive?

Windows may have somewhat slower load times and performance on an external drive, but with high speed interfaces like USB 3.0, Thunderbolt 3 or USB-C, performance differences are minimal for most usage.

Can I install any version of Windows 10 on external drive?

You can install any retail version of Windows 10 including Home, Pro, Enterprise, Education, etc. Ensure you have the proper installation media and product key.

Is booting from an external drive safe for my PC?

Booting from an external drive is perfectly safe. The Windows installation on the external drive functions independently and does not modify the host computer.


Installing Windows 10 on an external hard drive or USB flash drive is a straightforward process that anyone can complete in just a few steps. With an external Windows installation, you can take your entire PC environment with you anywhere. It’s a great way to provide computing mobility, troubleshoot computer issues, save money on Windows licenses, and have a backup handy if needed.

Just make sure you use a high-quality fast external drive, follow the steps carefully during installation, set up device drivers and software, and create a system image backup once the installation is complete. This will provide you with a fully functional and portable Windows 10 experience that can start and run from any compatible computer.