Install Windows 7 on USB Flash Drive or External Hard Drive

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.