By Lucas / Last Updated August 10, 2022

I am trying to extract the ISO of Windows 10 to a partition on my external hard disk. But when I boot my device through the external hard disk, my computer displays that no OS was found. My hard disk is 1TB which has four partitions and I have extracted the ISO on partition no.2. Can I format partition no.2 but don’t format other partitions of my external drive as they contain my data?

- Question from Windows Community

Install Windows 10 from an external drive

This part tells how to create a bootable windows 10 external hard drive for installation and how to install windows 10 from the external drive It can be divided into two sections:

Section 1: Create a bootable Windows 10 external hard drive

This section will introduce how to create bootable windows 10 on your external hard drive. for Windows installation.

First, please download the Windows 10 ISO files from here, and make sure the external hard drive has free space larger than 5GB.

Step 1. Press Windows and R together, type diskpart, and click Enter.

Step 2. In the CMD window, please type the following command step by step:

diskpart
list disk
select disk # (number of your external disk)
clean
create partition primary
select partition 1
format fs=ntf quick (If you need to create a UEFI bootable USB, you should type format fs=fat32 quick)
active

Step 3. Type Exit to end it.

Create bootable USB

After the above steps, open File Explorer, and copy and paste all the contents of Windows ISO to your external hard drive.

Section 2: Install Windows 10 on a computer from the external drive step by step

After you have a windows 10 bootable external hard drive, you can enjoy your windows wherever you are, let’s follow the guide to finish your windows 10 installation.

This is a general method to install Windows 10 on your computer, which is a little complicated, please follow the instructions step by step. Once you download the official Windows 10 installation media for free from Microsoft (You can download it from here.),insert the external hard drive.

Step 1. Launch the download file, and choose “Create installation media(USB flash drive, DVD, or ISO file) for PC in the “Windows 10 Setup” popup window.

Step 2. Select your “Language”, “Edition” and “Architecture” which is your CPU version.

Step 3. Choose the media you want to use, a ”USB flash drive” with a capacity larger than 4GB or an” ISO file”.

Choose media

Step 4. After you create an installation media, you need to access the BIOS, restart your computer, and press a required key as the screen shows. Generally is “DEL” or “F2”.

Step 5. Now, choose the “Language to install”, “Time and currency format”, “Keyboard or input method” and click “Next”.

Windows set up

Step 6. In the Setup window, click “Install now”.

Windows install now

After the above steps, you will see “Activate Windows”.

Step 7. Enter your key if you have one, if you don’t, please click “I don’t have a product key”.

Activate

Step 8. In the new window, select “Custom: Install Windows only(advanced)”.

Custom install

Step 9. Select the drive you need to install Windows on and click “New” and then click “Next”.

Place windows

Warning: In this step, your files will be formatted.

Installing

Now your Windows will install and restart several times.

An easy way to Install Windows 10 on your new hard drive

This part is about how to install Windows 10 on your new hard drive easily, the content should be how to clone OS from an old hard drive to the new one, rather than a fresh install.

As mentioned above, the manners of installing Windows 10 from an external drive are involved that many novices operate hardly. To install Windows 10 on your new hard drive simply, you can use AOMEI Partition Assistant Professional to migrate Windows 10 from the old hard drive to the new one. And based on the hot clone method, you can run your current system when the migration is running. You don't need to restart your PC.

Download Pro Demo Win 11/10/8.1/8/7/XP
Secure Download

Here are the detailed steps:

Step 1. Install and launch AOMEI Partition Assistant Standard.

Step 2. In the left menu, select the "Migrate OD to SSD" function.

Step 3. In the new popup window, please click” Next”

Next

Step 4. Choose an unallocated space on your disk.

Select space on SSD

Step 5. Now you need to resize the size of the partition, and click” Finish”.

Resize partition

Step 6. Then, you can see a note about how to boot OS from SSD or HDD in the new window, keep it in mind and click "Finish" to continue.

Migrate

Step 7. Click “Apply” in the upper-left corner.

Apply

To sum up

In the first section, you can see a common method about how to create a bootable Windows on an external hard drive and install it from your external drive, however, it’s a little difficult for many users to operate. In the second section, as you can see, AOMEI Partition Assistant provides you a more operational possibility to install Windows on your new hard drive, which is a more apposite way for amateurs to improve the success rate.