How to Boot Windows 7 from External Hard Drive Successfully?

February 25, 2019

There are chances that you need to boot Windows 7 from external hard drive. This article demonstrates how to create bootable media and boot Windows 7 from external hard drive.

Scenario

“I have a Dell desktop and the operating system installed on my computer is Windows 7. I want to format all the partitions on the original hard drive. But when I started to format C drive, the option of “Format Partition” was grayed out. I was told that it was not allowed to format C drive within Windows and I need to format the system drive from somewhere rather than the Windows installation. I know I can make a bootable Windows PE bootable media and then boot Windows 7 from the external hard drive to manage disk. I just wonder what should I do to make bootable external hard drive and then boot Windows 7 from it? Any suggestion shall be appreciated! Thank you!”

Create bootable Windows 7 external hard drive

As what mentioned in the “Scenario”, it is wise to make bootable media to format C drive. In such circumstance, you can turn to third party software like AOMEI Partition Assistant to create Windows 7. This powerful professional freeware can help you to create bootable media within few clicks. What’s more, it is featured with many functions base on disk management as well. It is possible to extend C drive without data loss and shrink C drive beyond half via AOMEI Partition Assistant. If you upgrade it to Professional version, you can enjoy more features like converting dynamic to basic without losing data and allocating free space from one partition to the partition that you need to extend.

Something that you should know before operation:

  • It is available to create bootable media via AOMEI Partition Assistant whether your device is CD/DVD or USB drive.

  • When your operating system is Windows XP, please download Windows AIK to configure and deploy OS to new hardware.

  • As all the data on the external hard drive will be formatted during the process, it is recommended to backup your important data on the external hard drive.

Detailed steps to create bootable external hard drive

Then, you can do as the following steps (Take creating bootable USB for Windows 7 as an example):

Step 1: Connect USB drive to your computer and make sure it can be detected by your PC. Then download, install and run AOMEI Partition Assistant. Click “Make Bootable Media” and click “Next”.

Make Bootable Media

Step 2: In the pop-up window, select one way to create bootable media (Here choose “USB Boot device”). Then, click “Proceed”.

Choose USB Drive

Step 3: You’ll be noticed that all the data on the USB drive will be formatted. Click “Yes” and wait for the finish of the process.

Tips:

  • If you have no external hard drive, you can make a bootable ISO file via AOMEI Partition Assistant. At this point, third party burning software is needed to burn ISO file to CD/DVD or USB.

  • If you want to apply the same Windows when you’re in different place or keep home and work use separate when using same PC, you can use AOMEI Partition Assistant to create Windows To GO USB drive.

How to boot Windows 7 from external hard drive?

After creating bootable external hard drive or making Windows TO Go USB Drive, you can take steps below to boot Windows 7 from the external hard drive (Take USB drive as an example):

Step 1: Reboot computer and press certain key (Normally, it is “F2” or “Delete”; if not, you can refer to the PC’s manual or website to find out the right key) to enter BIOS.

Step 2: Then, select USB Device and hit “Enter” to boot form USB flash drive.

Boot from USB Device

Then you will enter WinPE environment and you can run AOMEI Partition Assistant to format C drive or something else.

What if the external hard drive won’t boot?

Generally, after creating bootable media and adjusting boot order, you can boot Windows 7 from external hard drive successfully. But it is possible that you are unable to boot Windows from the USB drive or other external hard drive. If you are trapped in it, you can do as follows to solve the problem.

First of all, you should enter BIOS to check the boot order. The problem that external hard drive won’t boot is mainly caused by inappropriate BIOS configuration. If there BIOS configuration is OK, you can remove other USB devices and try to boot from external hard drive again. If it still won’t boot, you should to consider that whether there is problem with file system of your external hard drive. When you try to boot Windows in UEFI mode, you should make sure that the file system of the bootable USB drive is FAT32. If your USB drive is NTFS file system, you can convert it to FAT32 without data loss using AOMEI Partition Assistant. Then you can boot your Windows from USB drive successfully.