By Jessie / Last update November 3, 2022

User Case

"I'm using a Lenovo Essentials laptop that has an unmodifiable partition table (due to recovery crap) and has all 4 of its partitions spoken for (3 primary, one extended, cannot change the extended). Anyway, what I  want to know is if it is possible to clone my hard drive to a USB external hard drive, and then boot off of it when I need to.”

If you have encountered a similar situation, you can find the solution below. This article lists some common reasons as well as offers the specific method.

Reasons for Cloning Hard Disk to USB External Hard Drive

People may need to clone a hard disk to a USB external hard drive for different reasons. There are some common reasons below:

  • Data Backup: Many users choose to clone hard drive to external hard drive for data backup. It can effectively protect data from virus attacks, hard drive crashes as well as disk corruption.
  • System Migration: Some people will choose to clone the system to a USB external hard drive because you can use your system without reinstalling it. If your target device is a USB flash drive, not a USB hard drive, you need to know how to clone SSD to a USB flash drive.
  • Hard Drive Upgrade: If you want to upgrade HDD to SSD but don't have an adapter. You can use the USB external drive as an intermediate media to do this. First clone the HDD to the USB, then boot from the bootable disk and clone the USB to the SSD.

Best Hard Drive Cloning Software - AOMEI Backupper

AOMEI Backupper Professional is a full-featured disk cloning software, including disk clone, partition clone, and system clone which can meet your different needs. It can help you clone a hard disk to a USB external hard drive easily. As an excellent cloning software, it has the following advantages as well:

Ensure secure boot: After cloning the disk, you can boot your computer successfully with the cloned USB drive.
Intelligent clone: Under the default mode, it only copies the used sectors and therefore you can easily clone a larger HDD to a smaller SSD if you need. 
SSD alignment: If your target disk is an SSD, this feature can accelerate the reading and writing speed of it.
Sector by sector clone: It will clone all sectors whether they are used or not.
Multiple disk types: It supports clone hard disk to an external USB drive, SSD, HDD, etc.
Different system: It supports Windows 11/10/8/7/XP/Vista, etc.

Clone Hard Disk to USB External Hard Drive Step by Step

Before you start cloning hard disk to USB external hard drive with the best disk cloning software, you need to do some preparation work first:

  • Back up the important files on your USB external hard drive, because the data on the target disk will be erased during the cloning process.
  • Check the capacity of the USB external hard drive. You need to make sure that the used space of the target disk is bigger than the original one.
  • Connect the USB external hard drive to your computer and ensure it will be recognized.
  • Download and install the best cloning software - AOMEI Backupper.
Download Demo Win 11/10/8.1/8/7/XP
Secure Download

After completing the preparations you can follow the graphic tutorial below to clone your hard disk to a USB external hard drive.

Step 1. Open the AOMEI Backupper Professional, and click Clone > Disk Clone.

Choose Disk Clone

Tip:

Professional edition supports cloning both data disks and systems disks from MBR to MBR/MBR to GPT, or GPT to  GPT/GPT to MBR. If you only want to clone data disks, you can pick the complete free Standard edition.

Step 2. Choose the original hard disk as the source disk. Then, click Next.

Choose Source Disk 2

Step 3. Choose the USB external hard drive as the destination disk. Then, click Next.

Choose Destination Unallocated HDD

Step 4. Confirm your operations and click Start Clone.

Disk Clone Preview Align SSD Checked

Notes:

  • Edit Partitions: You can change the partition size using this feature.
  • Sector By Sector Clone: It will clone all sectors, whether they are used or not. And it is available for cloning to disks of the same or larger size. So you can clone disk to larger disk easily.

Summary

When you need to clone a hard disk to a USB external hard drive, you can choose a professional disk cloning software - AOMEI Backupper to help you. It not only allows you to clone your hard drive to a different location (USB drive, SSD, HDD, etc.) and a different system (Windows 11/10/8/7/XP/Vista, etc.) but also allows you to boot your computer directly from the cloned disk after cloning.

Besides, you can use it to clone a large disk to a small one. Furthermore, if you need to clone a small disk to a large one or a disk of the same size, you can use Edit Partition to change the partition size.

In addition, it offers a lot of other features, such as system backup, file backup, etc. If you want to enjoy more amazing features, please download and use them!