Is it possible to install Windows 7 onto a USB drive?
You probably have heard of Windows
8 to Go, which allows you install a portable version of Windows 8 on a Microsoft
certified USB flash drive. If you are addicted to the old operating system (OS)
Windows 7, you may wonder is there a way to install Windows 7 on USB removable
storage device?
With Windows 7 on a USB flash drive or external hard drive, you can take it with you
wherever you go and run Windows7 on any PC.
Windows Setup can detect USB hard drive, but when you select the external drive as
the target location to install Windows 10/8/7, you will get the error “Windows cannot be
installed to this disk”. Luckily, there is a workaround for this, and it is
quite simple. Even those who does not know how to install Windows from a USB drive
can follow this guide to get it done,
What do you need to prepare?
You may have read some other tutorials or guides talking about installing Windows 7
on external hard drive, but the process is cumbersome and not easy to follow. Here,
I will recommend you a free tool AOMEI Partition Assistant that can do this trick
for you, so you only need a few clicks.
It provides Windows to Go feature that not only allow you to run Windows 10/8/8.1
from USB stick, but also install Windows 7 onto USB removable storage devices. It
does not require Microsoft certificate USB drives.
An external hard drive or USB flash drive that has more than 16GB of
capacity. For better performance, it is recommended to use a USB 3.0 drive, and
of course, you need to connect it to a USB 3.0 port.
Windows 7 installation file with file extension .iso, .wim, or. esd.
A working PC running Windows 10/8/7. Any version is okay.
Free disk partition manager software AOMEI Partition Assistant Standard
Edition.
How to install Windows 7 to external hard drive?
Before you do, you must know the USB external drive will be reformatted to NTFS file
system. If there are any valuable data on it, you should save it to another location
beforehand. When you prepare the things listed above, you can follow the steps below
to create Windows 7 USB install.
Step 1. Download and run AOMEI Partition Assistant.
Connect the external drive to your PC.
Step 2. In the main interface, if you see the USB drive is showing in AOMEI Partition
Assistant, click on the option Windows to Go Creator in the left panel. Otherwise,
you should check is there is a connection problem.

Step 3. In a pop-up window, click Browse to select the Windows 7 installation
file, ISO, ESD, or WIM format is all okay.

Step 4. Click Proceed to start this operation.

When the process finishes, you use this new created bootable USB drive to boot any
Windows PC and bring this portable version of Windows 7 with you.
As you see from the screenshot, the USB flash drive used to install Windows 7 is an
MBR disk, which means it can only boot PCs with Legacy boot mode enabled. If you
want it to boot UEFI boot mode computers, you can convert it to GPT
disk without data loss.
Besides the ability to install Windows 7 on USB drive, AOMEI Partition Assistant
Standard also provides many other great features, like Migrate OS to SSD without reinstalling Windows, Merge
Partitions and Resize Partition without data loss.
If you need more advanced features like convert dynamic disk to basic without data
loss, you can try the Professional
edition of AOMEI Partition Assistant.